Howdy yall!
Jack again.
We received some reports about extremely low FPS on a few Windows 10/High end GPU machines, and after some extensive QA have released a build that affects something called the Windows sleep margin. Apparently if the buffer isn't set to a certain value on some machines, certain game events can cause CPUs go to absolute dookie.
If you're having sub-60 FPS at runtime, please set your branch to [Experimental] and give the sleep margin fix build a try.
Hopefully this gets it sorted out!
Thanks again for all the reports and sticking with us :)