For Developers out there reading these forums, I have contacted support about this and is seems to be isolated to using a Mac. I can run on Windows 10 using bootcamp on the same hardware so I suspect it is interaction between AMD video driver and W3: Reforged. Ticket with support is 74470066.
Setup: MacOS 10.15.6, Vega 48 video card 8 GB Memory, iMac 2019 with 5K screen, 64 GB RAM (but also tried 8 GB of RAM/different RAM chips), 3GB Fusion Drive.
Playing in windowed mode help recover to main OS without reboot, but crash seems to occur no matter what I set for resolution or other video settings. It seems random as far as timing. If I play in full screen, it can cause the computer to force restart! Not good. Apple Support confirmed there is no obvious hardware issue with the iMac. That leaves some sort of interaction between the video card and the game.
All other Blizzard games I have and play on this hardware at max video options runs smooth and no crashes. Even other memory and CPU intensive apps on the computer will run without crashes.
Please work a bit more closely with Apple to figure out what is going on between the game and the video card.
Thanks,