After installing High Sierra 10.3.3, I tried to open Scrivener 3 and it simply froze/hung, requiring a Force Quit every time. My machine is an 11.6-inch MacBook Air (Early 2015), 2.2 GHz Intel Core i7. Bug reports sent to Apple. Tried attaching bug report for your reference but got a “File too large” error message.
UPDATE (January 27): I booted up in Safe mode and was able to repeat the hang.