Quick update. Ran the game through steam with this launch option:
"C:\Program Files (x86)\Steam\steamapps\common\Baldurs Gate 3\bin\bg3_dx11.exe" %command%
which just launches the game without the launcher. Seems to have fixed it for me, at least today. 6 hours of play, no crashes. I did try running both game executables direclty as admin, both immediately crashed. No idea why.
Hopefully that's helpful to some of you.
Well, new patch dropped and after a week of incredibly minimal crashing (literally hours of gameplay without crashing) now I'm back to crashing every 15 minutes or less. So that really sucks. Would really help to actually get some kind of official troubleshooting or something out of the support folks, just so we at least have some idea of what to try, instead of flailing for rumors on here and reddit.