The Malevolent trait Slave Masters is still bugged. In last night's game I had three trade routes established from my home world to AI's. When I took this trait, indeed my routes were now of the type Slave Trade Route, but I received no benefit from them.
I've noticed in the past that only routes created after taking this trait give any benefit and that benefit is a nearly meaningless +5% manufacturing per route.
So to be fixed.....
1) All slave trade routes should provide benefit from the slaves brought back.
2) +5% manufacturing applies to the basic minimum rate which by this time is typically +several hundred% due to many improvements on the HW. This is nearly meaningless. As slaves would improve overall productivity I suggest +1 Raw Production for each slave trade route for the originating planet. (Perhaps even +2 RP should be considered).
thx .. neilkaz ..