My old notes say so: viewtopic.php?p=33859#p33859
But that's a temporary local bonus, I don't recall how subjugation of minor races affects base morale (usually set from a 'controlling empire' table in race.rst IIRC).
There was also a conversation on correcting building stats (mainly minor race special structures IIRC), I don't recall where.
Many building stats in BotF appear unbalanced and just unfinished (including discrepancies between files).
In ECM we can't fix them due to missing correction guidelines, but you guys have more freedom.
Some examples:
- almost all klingon special structures are set to one-per-empire, not home system
- extreme energy costs for eg. Singularity Plant & some cardassian special structures like Obsidian Order (they have too few of them btw)
- some kinda useless minor-race buildings (energy cost, unfitting bonus output, build cost eg. Mintaka Farm)
Also if I missed any questions wrt minor races vs difficulty level I'd need a reminder link to it.