That would means it's basically "for free" again. In my current game I have 34 colonies, 9 of them have influence focus (capital race Eaxaw -> only average influence). Getting -1 on all colonies and +5 per influence focus would currently increase my net influence output by 11.
Compare it to other Stability effects:
- Martial Law gets even more than 10 points, but costs a lot of research and it does not raise stability above 15, so you still miss some of the better effects. I guess it may work well, if you can do research on planets that have 15 without it.
- Diversity gives stability and research. It's really strong when there are lots of natives (*), but you need a lot of races to come even close to 10 points.
- Environmentalism only gives 5 points and other bonuses, but only to planets that haven't been terraformed, have no buildings and do not have industry focus, while reducing industry an all planets by 5.
I'll try Trith next, I have a feeling they may be hard to play at the moment.