I am pretty sure it's a display/video driver issue and would like to just disable anything I could to that effect since this will be a headless system. Any suggestions on what I can do to troubleshoot this further?
Have you tried booting bsd in single-user mode? Have you tried booting a different OS (e.g., Arch Linux) just to check if _something_ works? Since you want this to be headless, why not configure your system to use the serial console? Your motherboard comes equipped with four serial ports, so use one. This does not address the bug-if in fact there is one-but it should at least allow you to work around it. I very recently ran into a similar issue with a new system I built. I was able to boot bsd.rd as well as bsd in single-user mode; however when booting bsd normally, it would hang after fsck(8) ran. This happened with the most recent snapshot as well. I was able to successfully boot Arch Linux without an issue though. Finally, I was about to send a bug report following https://www.openbsd.org/ddb.html where it recommends using the serial console to capture output. Once I bought the necessary equipment to do so, I re-enabled the serial console on my motherboard that I disabled before thinking I wouldn't use it. It turned out that the problem was disabling the serial console. Once I enabled it and installed OpenBSD with com0 as the default console, everything worked fine. I am happy this happened though because I would rather use the serial port anyway.
