I installed openWRT from a factory shrinkwrapped E8450 using https://github.com/dangowrt/owrt-ubi-installer. It was successful and I used it for a few days with only minor issues getting my setup the way I hoped.
While debugging another issue, I realized that the recommended version of owrt-ubi-installer that I used was quite old (to avoid the Kiss of Death on this hardware) and I needed to upgrade from OpenWRT 22.03.3 to a more recent version. Attended sysupgrade in LuCI couldn't quite handle 22.03.3 -> 23.05, and only offered to go to 22.03.7. Since this was my first attempt at an openWRT upgrade, I decided to do the 22.03.7 upgrade as a test run. It built the image with my packages and retrieved it successfully.
After initiating the upgrade, the web interface and ssh connection went down as expected, but it's still down after several hours.The main power light on the router is on but no other lights. SSH and web connections are timing out.
Power cycling during a sysupgrade seems very risky, but i don't think there's any other way i can interact with the router. Anything else i can try at this point?