I made the change for unhandled instructions.
After MR346 it remains impossible to actually compile any shader which needs an interpolation mode, and very unlikely to compile one which needs the DXIL signatures.
Do we still need the special case for compute shaders in patch 2/3 then?
Are there any remaining issues which would hold up MR320,345,346 in general?
Not in general, no. I did have some comments on !346 specifically though, and it's marked as a draft, of course.