I should have provided an update. The issue did re-occur for me. Similar results as what you listed. Sway freezes instantly, FVWM and CMW after a short period of time with both Firefox and Chromium when accessing video content on YouTube. Badwolf seems to be okay, but I do not know if it is enabling GPU hardware acceleration.
I have not had the system freeze up when an external monitor is attached. Sway works, and web browsers all seem to work.
I did file a bug report, but I don’t know that I had enough information to take action on.