I notice in the features of this mod you list:

• AI more likely to use subjects in order to expand

I've been thinking myself about trying to tweak the AI's use of subjects similarly to make the AI more likely to acquire subjects (I'd also like to make subjects more likely to rebel - this seems to be possible mechanically, but I think there's no weighting so the AI literally never does this?)

I'd really appreciate any tips or explanation you can give - AI modding seems quite daunting, and I can't find much documentation.

I've had a look in your mod's files, but i can't see very clearly what you've done here. Is it in the GAI_plan_goals file? I can't see anything referencing subjects directly, so is it about Aggressive Expansion preferences?