Thus far I have not encountered any issues with your mod. Obviously it isnt compatible with mods that change or alter the races looks like all the Dimorphism mods and the few additional clothing/colored mods but that is to be expected. I have not played a full game with your mod but I would be wary of two things which someone else or yourself can look into which is Ai using your portrait groups or obviously gene modding.

The game itself is bugged with a possibly rare glitch where the game will start the refugee event chain which can bug out an entire Ai Empire's portrait. I've only encountered the glitch once but it is of relevence because the grouped portraits could have the same effect but 2-3 hours of playing seemed fine with your mod.

I have never encountered this event in my games, but I'll look into it. Thanks for the feedback, good to hear that there are no gamebreaking bugs.