If instructed how, I would definitely be willing to bisect.

Power went out, fell asleep, no xorg logs during the day. Sorry for the delay,
a working log/dmesg combo on 4.14.35 coming up shortly, for reference.

This breaks on any kernel 4.15 and above, by the way. Decided to report it
against whatever is present in 4.17, since the issue still persists there.

And if I can get rc4 to install, I'll test that and provide the logs from that.