I've actually managed to fix it, annoyingly easily. I'll post my findings here in case any other person is searching around like I was, and couldnt get it to work.
For me it was very, very simple: Make sure you have no prior version just in case, the FAF client mod version is only V12, not V13, so make sure its not in the mods folder at all just to be safe
Download the V13 mod as linked above
Rename the mod folder, as instructed above, to 'rks_explosions'
Youre done, thats it, it works out of the box for me. It was modifying the lua file that was breaking it just like V12 is broken, causing weird changes in spawning, animations, enemies, campaigns, and even skirmish maps.
Im not sure why I had this issue where ZBC wasnt having it, though, maybe we have different versions of FAF launcher? I downloaded mine just last week from the main website, considering the mod on the FAF launcher is outdated despite being published in 2020 yet updated between then and now, im willing to bet there is just a general lack of maintenance causing issues with versions that makes V13 work for me but not ZBC.
Personally I find it shocking I didnt see the V13 version anywhere despite dozens of minutes of googling, the FAF client is several years out of date with the mod, which is tragic since thats how most people will find and install the mod - and it wont work. Not only is it hard to figure out its that specific mod causing issues, I mean "its just a graphics mod, why would that mod stop the commander spawning or place a T3 cybran destroyer in my base at spawn?" but its such a good mod that id consider it one of the top 10 essential mods, just with how good it makes the game look.
The mod listed on the FAF website under its own page is only V12 simply stating V13 is "coming", since that was 2020 any normal person would assume it was abandoned. and then assume its just forever broken.
The mod on modDB is also only V12.
Its by pure luck and chance I just happened to google the right combination of keywords to find this thread and my answer and a link to the V13 mod, despite literally searching RK Explosions, if I hadnt found this thread id never assume V13 existed. Itd be nice for all the relevant pages to be updated with up to date mods or links, especially the launcher.
Anyway I want to thank ZBC, not only for trying to help, but also instructing me about changing the mods folder name, even though for me the V13 mod worked without editing, I would never have known to check that one specific lua, nor to identify I needed to rename the mod, for it to work.