I am still not convinced it is a "hardware" issue, but we will see.
I don't think anybody is suggesting it's a hardware issue.
Based on my experience (25 years in OS development) the issues I experienced and described elsewhere in this thread look, swim, and quack like a display driver issue. Yes, possible something unrelated but not where I'd put my money if placing bets.
I swapped out my Pro Vega II system for a Pro Vega II Duo last week (so 3rd ProVega system now). The system has been up and running for over a week without so much as a hiccup. The same held true for the system prior to it (non-Duo Pro Vega II) which went 4 weeks -- rock stable. This is in stark contrast to the two W5700X systems that I started my journey with, which were unusable for my work due to how unreliable they were.
I addition to my development tools, I've installed and used several CC apps (PS, LR, AI) on all of the systems, in addition to Capture One and Resolve. So, to sum it up:
16-Core W5700X (Unstable)
24-Core W5700X (Unstable)
24-Core Pro Vega II (Stable)
16-Core Pro Vega II (Stable)
24-Core Pro Vega II Duo (Stable)
As I've indicated before, I have zero doubt that Apple is well aware of the issue and it's just a matter of time before a fix gets out.