Thanks for the answers guys
I was able to get some feedback from someone at Allegorithmic, and the issue comes from my GPU driver... I recently upgraded to a GTX 1080 from Macvidcards, which runs with Nvidia-provided drivers and uses metal. From what I was told Allegorithmic only supports official Apple drivers, so here we are...
I previously had a GTX970, also from flashed by Macvidcards, and it worked fine.. but the 1080 uses Pascal (which also causes some issues in After Effects)...