If I’ve understood you right only shield bubbles overlapping the aoe of a shot take damage? Which sounds similar to steam/non-faf implementation which would make stacking shields much more powerful and hence make turtling more powerful.

v309 Update
24 changes, mostly relating to some AI vs AI games run as part of the 10km version of the 'Vs M28AI' AI tournament, including:

• More shield boats are built if enemy has a novax nearby
• Increased ACU aggression in assassination modes if it's behind on eco
• Improved M28's ability to rebuild power outside of the main base if almost all its core base power is killed
• T3 land should be obtained quicker if M28 has lots of t2 support factories
• M28 should be less likely to upgrade multiple T2 mexes to T3 if it lacks any T3 mexes
• Added a couple of basic chat responses

Acknowledgements

• Nomander - Helping with identifying a function for reading chat messages sent by players (which I’d mistakenly dismissed as only being relevant for resource sharing messages).
• Radde – 3 replays against M28
• Relent0r – 2 replays of team games vs M28

v308 Update
7 changes, mostly relating to forged alliance mission 6, including:

• Amphibious units that are underwater should prioritise moving to defend a nearby friendly land zone under threat over suiciding into a nearby enemy base
• Shorter ranged direct fire units should consolidate if they're closer to the enemy than longer ranged units they're meant to be supporting
• Units should no longer run from enemy gunships if they're in range of enemy land units

I've now finished updating the Supcom and FA campaign difficulty ratings based on what AIx modifier M28 needed to solo the campaign missions. It's now capable of beating every mission at 1.0 or less, with the exception of the remastered Cybran Mission 6 Freedom (which marks a significant improvement on before where M28 also needed higher modifiers to complete missions 1 and 6 of the forged alliance campaign).

v307 Update
15 changes, mostly from forged alliance campaign mission 5, including:

• Replaced previous asf hover-micro with stop-micro (I'm assuming at some point asf values changed which meant hover-micro isn't as good, as I was unable to hover-turn asfs and the logic was performing worse than just moving to the enemy/no micro when the enemy used stop-micro; e.g. in a 50 vs 50 asfs fight, M28's old logic resulted in 38 enemy asfs surviving to its 0, whereas with stop-micro and a couple of other minor changes M28 won the fight with 32 asfs surviving)
• MAA should avoid indirect fire units (not just direct fire units)
• Fixed a bug where M28's ACU could cancel an upgrade part way through if it had previously started reclaiming something and an engineer then finished reclaiming the wreck
• Pond values should be reassessed in campaign missions and factor in the playable area
• Asfs should be more likely to commit the entire air force against enemy asfs if taking an air fight
• M28Easy should do very basic kiting with a fatboy if enemies get close to it

@Nomander
Ythotha was the main unit I had in mind where it'd be beneficial as I'd have thought fatboy's firing nature means it deals much higher DPS against a bubble shield than it does normally (all its shots hit); but I was thinking not just as a standalone unit if it might be worthwhile but also compared to old bubble shield which was rarely seen and would also give aoe protection to percies.

Since megalith's firing nature is a bit easier to control in sandbox and you've suggested it as a use case, I figured I'd run some simple sandboxes to test my theory that I'd be better off just getting more percies vs getting percies+new bubble shield (as if that's an example of the bubble SACU use case, I'd expect it to come off reasonably well).

Granted this isn't perfect 'live-game' type scenario since you wouldn't expect a megalith to be unsupported, but it does still give useful information on how the new bubble shield compares.

I'd kite the megalith backwards after it started firing (until all percies were in range of it). Percies would start off grouping in a 2 line group before advancing as a group. Effects of crash damage were ignored (as that was reliant on at what point I got around to just having percies attack when switching army views).

• 25 percies vs 1 megalith: 4 percies survive
• 17 percies + 2 new balance shield SACUs vs 1 megalith: 3 percies survive
• 19 percies + 1 old balance shield SACU: If the shield SACU is grouped with percies and advanced such that the megalith fires at the unprotected percies first, mega wins; if instead the shield SACU is put slightly ahead of the percies so a kiting megalith targets it down first, then 8 percies survive.

Worth noting in most cases this setup would be expected to be favourable to the shield SACUs - 2 new balance shield SACUs with 17 percies mean the shield SACUs cover every percy, without the shields overlapping. I'm also ignoring energy costs, or the cost of building a gateway (essentially assuming they're free). One other thing that might give the shield SACU a better result is if say it was x3 the number of units so percies took more aoe damage from the megalith, but then there'd be shield overspill balance to counter it.

TLDR sandbox results

• Getting more percies results in a better position than mixing percies with new bubble shield SACUs
• Old bubble shield SACU gives a better result if the megalith can be baited into firing at the shield SACU first (and/or if the percies can all fit under it initially I expect, but that'd be harder to micromanage)

#27323961
#27324001

v306 Update
16 changes, mostly from having M28 complete forged alliance campaign missions 2-4, including:

• Units dodging shots that would move off-map should look for alternative angles, while ACUs that don't want to retreat but who lack a factory (e.g. start of M2) shouldn't dodge away from the enemy
• Expanded cases where M28 will treat its original base as lost and treat a new location as its new core base
• Air factory upgrades should be obtained sooner by sub-1.0 build modifier M28s
• T3 sub hunter and atlantis's anti-air threat is greatly reduced when submerged
• Fixed a bug with t3 arti and mavors that meant they were calculating the angle they were facing at a 90 degree offset (which on mission 4 caused the mavor to fire 1 shot north, and immediately rotate to fire 1 shot south, causing a massive decrease in dps)
• Fixed a bug where requesting an engineer from M28 could crash the game

Acknowledgements

• Tollan – Replay and highlighting the game crashed when requesting an engineer.

Re Q2, sucks to see the bubble shield nerfed so hard for what already was a unit I'd rarely see. Using mass costs for simplicity, before it was 7600 mass (2100+2000+3500) for a 55k shield [i.e. 7.2 shield per mass] that would (when discharged or down) regenerate at 256 health/s (150 when up).
Now it's 5200 mass (1700+3500) for a 22k shield [i.e. 4.2 shield per mass] that would (when discharged or down) regenerate at 200 health/s (160 when up).

As a comparison, Sera T3 mobile shield although significantly smaller, benefits from far better speed of 4 (2.2 for the SACU), and costs 720 mass for a 10k shield [i.e. 13.9 shield per mass] that when down regenerates at 250 health/s (133 when up).

In terms of potential value from a UEF perspective, a percy gets 5.6 health per mass investment; granted this shield protects from aoe damage, but at the same time it also takes damage faster because it's easier to hit with indirect projectiles (far more so given its size compared to other mobile shields).

Before the shield was so high in health that it could both be used as an alternative for base defences in some scenarios (e.g. I found it made a good tele defence for smd/arti/game enders compared to static shields where a SACU could teleport in and its death explosion could kill the static shields), and was an option for covering slower attacking units with the defensive buff justifying delaying the army a bit. The shield would recharge painfully slowly and coupled with the slow SACU speed it was difficult to get continued value from them (compared to mobile shields).

Now it feels like that's been made even harder - it still has the really slow speed compared to other mobile shields, but no longer has the high health to compensate. It's also (vs single target damage) more efficient to just get percies vs getting a mix of percies and shield SACUs. I presume the intention is therefore for it to no longer be used primarily as a shield unit, but instead as a hybrid combat-shield unit, but also one where the increase in damage spill means it's worse in numbers (with its large shield size harming building it in larger numbers disproportionately compared to the other mobile shields, since it's more likely to overlap with other shields; the bulwark would be a useful counterpoint for where a high shield size can still work, but the bulwark is significantly faster and the shield size so large it doesnt need to be on the frontline). But if it's only intended to be built as a single unit to support an army, it then works out even more inefficient unless the gateway was being built for other SACUs (maybe the wider SACU changes mean it would be). So I expect I can still use it for teledefence (cheaper vs SACU tele, weaker vs tele-laser), but other mobile shield uses for it feel much weaker.

Appreciate you primarily wanted in game testing, whereas I usually approach things from a more theoretical 'if I had the apm to use this unit however I wanted, what use cases can I see for it', since I can then both have my AI apply those use cases, and use them myself as a player occasionally. However I'm really struggling to see how I'd be better off building percies, a gateway, and 1 or more of the bubble shield units vs just building percies (given the shield gives less health than the percy),

Also just checking how things compare at the t2 mobile shield stage re shield health vs combat unit health, t2 mobile shield gives 3k health for 220 mass (while being fast moving and recharging much faster). A pillar gives 1500 health for 198 mass. It's a similar story for othuums - i.e. T2 and T3 mobile shields give significantly more health per mass invested than an equivalent combat unit, compared to the new bubble shield SACU which gives less (so maybe its combat potential makes up for this, but then it's less of a mobile shield than before, when the rationale for the change was that it was being rebalanced with mobile shields in mind?)

v305 Update
29 changes, mostly from getting M28 to solo FA mission 1 with a 1.0 modifier (down from 1.3 before), including:

• Gunships should consider attacking nearby enemy units that have moved too far away from nearby enemy AA cover (even if the enemy overall has too much AA in the area)
• If a player's base is destroyed, M28 should consider assigning their 'base' to a further away factory (most relevant in campaign missions with timed expansions as otherwise M28 would try to avoid rallying units near the enemy base that it had wiped out some time ago, and it'd previously only reassess the enemy base location when the map expanded)
• Engineers shouldn't dodge a bomber if they're under a shield
• Factories to be paused when stalling energy should only not be paused if they're building engineers (and more are needed), vs before (where they wouldn't be paused if more engineers were needed regardless of what they were building)
• Fixed a bug that wasn't increasing stealthed ACU aggression, and increased ACU aggression more generally when high health if the nearest enemy units are a bit too far away from the main enemy army.
• Shoulder drones should be treated as engineers now (and no longer paused in sim city mode)
• In sim city mode players now have control of transports instead of M28

Acknowledgements

• @nomennominandum Highlighting bug with shoulder drones being paused in sim city mode (and suggestion re transports being included in player control)

v304 Update
25 changes from having M28 complete missions 4-6 of the Aeon campaign, including:

• T3 arti should consider other zones for targets if its first two fail to yield any targets (most likely where the units are outside the playable area), and should avoid firing near objectives that are to be captured (like the black sun control centre)
• TML missiles should be dodged once M28 has intel of the missile
• Increased pathing checks for land units to recognise when they can't path to a target location due to the playable area being smaller
• Naval HQs should be upgraded sooner if the old HQ is destroyed and M28 has support factories of a higher tech level

Thanks for the feedback, I'll make a note to include transports in the units that can be controlled (hopefully for v305)

In the case of SACUs though the problem is you can switch their upgrades around at will so there's nothing stopping turning a RAS SACU into a combat SACU (other than it being inefficient) so I'll probably leave them out for now.

Another significant advantage not mentioned is build time - you can build a soulripper in the time it takes for roughly 8 wailers - so it's great if you have lots of energy, mass, t3 engis, and want to quickly take advantage of an air win by your team.

I see it as a weak to average unit - not as good as czar, and nowhere near as good as ahwassa, but I find myself using it occasionally (usually where I've not managed my air grid scaling that well and find I have mass to spend).

Would be nice if it could have a bit higher health regen I suppose to lean more into the raiding role that iirc was the justification behind the previous changes that made it cheaper and weaker, but I'd be wary of buffing too heavily

v303 Update

• 2 Updates for Aeon M1 (redundancies for an issue where naval factories could get blocked by engineers they'd just built)
• 3 Changes for Aeon M2 (Getting T1 PD at the start of the game, self-destructing friendly units on an island with nowhere to attack when near the unit cap)
• 14 changes for Aeon M3 (including various adjustments to make the ACU both retreat into water when dying, and then pop out of the water to attack nearby land units, and adding a redundancy to cover cases where M28 loses its power and doesn't realise, so doesnt build more)
• 12 Changes based on an AI vs AI replay, including engineers not trying to capture part-built T1 mexes, ACUs being more aggressive, and plateau factories being less likely to build units if there are no enemies on the plateau and they're stalling mass.

v302 Update

• New sim city mode - M28 handles giving combat units orders while you focus on ordering around engineers and deciding what factories will build. Available as part of the "M28: Combined AI-Human armies?" game settings (along with the MOBA mode)
• 3 changes based on AI survival replay, including making units less likely to suicide into an enemy firebase, and prompting if the players haven't allowed M28 full control of attack waves
• 17 changes for Cybran Mission 6, including making aircraft carriers run sooner from enemy naval threats, mobile sonar no longer receiving orders as though it is an amphibious unit, and gunships and torpedo bombers being more likely to attack a nearby enemy if it is too far forward from AA defences in the area (even if the AA defences are too much for a more general assault)

Acknowledgements

• Rama - Highlighting M28 replay involving the AI survival mod

v301 Update

• 20 changes based on Cybran Mission 5, including M28 having a chance to treat another location as its core base if its core base is destroyed (so it's not completely out of the game); Land units that outrange the enemy navy should proceed with attacking other land threats if the navy is out of range; ACUs should engage non-combat enemies in their range instead of ignoring them when building; Cybran destroyers owned by players can toggle amphibious mode when built if M28 has control of them; Land units should be more aggressive against short ranged direct fire units that they can't see (and hope they get visual of them) rather than retreating and waiting for radar.
• 4 fixes for games in LOUD, relating to some error messages, Seraphim unit callbacks not triggering, and recognising the range of units with a depth charge attack.
• 5 changes to reclaim, including fixing an issue where engineers were meant to be prioritising high value reclaim in a nearby area but were instead getting the closest reclaim.
• Various changes to eliminate several error messages periodically appearing (relating to 'invalid args to yield' and 'call expected but got number') which mostly related to where I was trying to exit a function early by doing 'return nil'.

Acknowledgements

• Nomander – Providing a solution for toggling amphibious mode on player controlled Cybran destroyers
• Heaven1508 – Providing a log containing some error messages in a LOUD game relating to M28

Realised I forgot to post the v299 changelog

v299 Update

• 9 changes specific to Cybran mission 4's logic for not attacking the mainframe (due to it causing mission failure) to make units a bit less cautious around outlying areas and hence less likely for M28 to be stuck in a stalemate
• 11 other changes from Cybran mission 4, including fortifying the mainframe nodes, allowing M28 to get slightly closer to the unit cap before self destructing units, and having ACUs be aggressive if they are pushed to the edge of the map (so they dont just keep trying to run while being fired on)
• 2 Changes from other replays tweaking some changes made in recent updates

v300 Update
Since it's version 300, this was a very special update!

I forgot to disable debugging options when uploading v299, realised an hour later, and so v300 is just removing those debugging options...

You can do the same with gunships - group them up with distribute orders, and you can stack 80 gunships in one spot! If the group now attacks an enemy they only see a few gunships, so 80 vs 80 specter gunships the grouped will always lose. Generally it will be the ungrouped may lose 10 units.

@ZooDoo4U How is it unfair if both players can do it and there is a clear tradeoff to doing it?

They stack 80 subs, you do splash damage and kill/heavily damage 80 units with a single shot (the tradeoff/risk of doing it)

Or, they stack 80 subs, you stack your 80 subs, you're both roughly equal on the fight.

I also don't see how something is a cheat just because it is considered unfair.

@Defiant https://forum.faforever.com/topic/10117/player-modifier-pcx-balance-games-between-different-rated-players

https://forum.faforever.com/topic/9118/faf-statistics-megathread-2-statistics-boogaloo

It'll be in the mod folder, e.g.:
C:\ProgramData\FAForever\user\My Games\Gas Powered Games\Supreme Commander Forged Alliance\mods\PlayerModifierPCx

It applies a resource buff to every resource generating unit when that unit is created, with the buff being a factor determined by the game options

If you need help on modding more generally I'd suggest asking in the modding discord channel part of the FAF discord:
https://discord.com/channels/197033481883222026/832710161847287819