10.15.1 beta2 took me out

beta 1 was fine, but my RX-580 was booting to a black screen after beta 2 (worked fine for a couple of days IIRC, but then went bad)

-x booted fine but can't work with that mode.

hmm, I wonder if it was firing up the iGPU and using that port; forgot to check that output before I reinstalled 10.15 GM.

back in business on the GM in under 30 minutes at least.