For anyone who hasn’t seen it, I think a fix for this is in the works. There was a detail in the latest email update on the FW 16 shipping that sounded like it was addressing this issue:
Display frozen after smart MUX switching - AMD has shared an updated graphics driver with us that has the fix for this along with some new features and performance improvements. This is also currently in our test process, and it will follow the same release path as the BIOS update.
Edit: I don’t think the above has anything to do with Linux. Probably just a Windows driver.