Thanks for getting Slate 🙂
Regarding HDRP and Post Processing, currently Slate only supports v1 of Post Processing stack (whereas “I think” HDRP is using v2).
As such the only thing that could not work correctly, would be the “Focal Range” Parameter (for depth of field focus) found in the Camera Shot Clips. Other than that, I can’t think of anything else that shouldn’t work, but please let me know if so 🙂