Why can't CapStructure build around size16 buildings?

Messing with /lua/ui/game/commandmode.lua...

It runs SimCallback({Func = 'CapStructure' etc}) whenever you click a building to ring (IE, ringing a T2 mex with storage). This also seems to work on larger buildings (IE, T2pgens), but doesn't work on T3pgens or factories, I'm assuming because they're size16

Is there a way to change this, or is it hardcoded into the engine?

The functionality is entirely in Lua. It ends up calling this:

• https://github.com/FAForever/fa/blob/deploy/fafdevelop/lua/SimCallbacks.lua#L202-L373

Which, when made, did not need to support a structure of that size. You can adjust / add to the logic to allow that