So i blew up my first Mac Pro. Literally killed it with 4 screens looping 4K video for 24 hrs. On to #2. One think that i am seeing now that i am using the star tech active adaptors is that the screens do not ID correctly in the Catalyst software. For example Screen 1 is mapped to screen 1, 2 to 2, 3 to 3, and 4 to 4. If i switch 2 & 3 in the catalyst software they both now want to work on screen 2 and i can't assign anything to screen 3. I have tried a new set of preferences with no luck. I would think with the way you have set this up you wanted to allow us to fix a bad screen assignment by an easy software swap.