Just an FYI for others who might have any issues:
I installed the BIOS update using a Windows To Go drive, which worked fine for BIOS 3.03. It rebooted fine, and it went through the install like normal. After doing the EC update, it hung on “Update status: Complete”. I left it like that for about 30 minutes, and no change. I just tapped the power button (tapped, not held), and it turned off. I turned it back on, and was greeted with a black screen for about 25 seconds. After that, the normal Framework post screen came up, and it tried to start.
However, it just threw me into a Windows blue error screen (A required device is not connected). I rebooted to try and change my boot settings, only to notice that my Linux boot entry was gone (Arch on my NVMe drive), and it was listing Windows Boot Manager on the NVMe drive, while in actuality there’s no Windows EFI data on my internal drive, it’s all on the expansion card. I removed the expansion card, had no effect.
I tried an Arch USB, to reinstall my boot entry, but I then discovered that no new boot devices showed up whatsoever. Also, while I was in there I tried the power button dimming option in the bios when I first rebooted (it’s why I updated), and it didn’t have any effect. Still the same brightness.
At this time, I started to panic a little. I opened up the laptop, and I wasn’t greeted by the normal flashing LEDs when I first opened the chassis. Completely dark. I disconnected the battery, then (very carefully) removed the CMOS battery, waited a few seconds, and put it back in. I then reconnected the battery, and upon turning the machine on (and going through another memory training), everything is normal again. I was able to boot into an Arch USB and reinstall the boot entry, and the new power button dimming feature works perfectly now.
Hope this helps if anyone else has the same issue. It might be my fault for pressing power (given that it tells you explicitly not to do that in the initial program), but I didn’t know what else to do after it hung for a long time with seemingly no change.