The latest version of the plugin should fix the compatibility issue: https://forums.unrealengine.com/showthread.php?65857-Substance-Plugin-4-7-3-7-Released&highlight=substance
Double post! The latest build of Substance Painter, 1.3.4, is unusably slow in the viewport. I literally can not even put my mouse over the viewport without it grinding to a halt. It's only using 15% max (usually around 10-12%) of my processing, and doesn't appear to be grabbing tons of memory. But anything that requires…