This is not a regression. Tested in //UE5/Release-5.0 CL20379098
Editor crashes with an assertion after executing the command r.RHIThread.Enable 2
A warning to prevent the command since 1 or 0 is expected, or RHIThread would start running on that dedicated thread.
The editor crashes with an assertion:
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-174612 in the post.