OK I did well in the colony rush (Not always easy playing large with all 8 current AI opps) and there was a +20 mega event choice so rather quickly I have my Death Furnace on Drengi.
Indeed it is working properly and giving me more than +50% Raw Prod and when I mouse over RP is states that.
Ruthless also caused a large boost in Drengi's shipyard production but no where can I find a tool tip stating that.
Unforgiving may need a buff as by the time you get it, adding +25% to the base production figure isn't great since most planets have +200% or even lots more by then. Perhaps for those playing larger maps and able to get more IP from colonizing many planets it might help more. I urge you to try it and judge for yourself (save game first).
In summary, I find no bugs in the Motivation line from 1.41 to 1.5 opt.