I managed to get the Beta to crash again this morning on a Benchmark run. It displayed the first two results (Vector Single & Vector Multi), then hung before anything else was displayed. Same errors in event log as in my first post. The .exe was pegged at a fairly constant ~28% CPU usage and 0% GPU usage in task manager prior to writing the dump files and terminating it. I gave it what turned out top be around 8 mins from when the "Display driver igfx stopped responding" was logged in Event Viewer just to make sure it was definitely crashed...
The dump file (2.6 GB!) is here:
https://www.dropbox.com/s/9yn0pz0vrtnsx01/Photo.DMP?dl=0
Not sure if it was needed, but the dump from the crashhandler is here:
https://www.dropbox.com/s/s5ladsi58l4p57d/crashpad_handler.DMP?dl=0
Let me know when you've managed to grab them, as I could do with the space back in my DropBox.
Good luck!