Thank you, I appreciate the response. I attempted to be careful, but didn't get very far. I tried a test run of the
sudo clr-boot-manager update command, and it absolutely killed both the rEFInd and Linux Boot Loader, and caused the ESP to fail a filesystem check. I was able to
fsck that partition. However, nothing could recover the boot loader, be it formal solutions, informal solutions, or 3rd party solutions. Out of desperation, I reinstalled Solus, formatting only the ESP and
/root. I was up and running in no time because I keep my
/home on a different partition.
Finally, I was able to append the
echo 'iommu=soft' | sudo tee /etc/kernel/cmdline kernel parameter to Solus boot, but to no avail. I tried setting my UEFI with and without Legacy Support; with and without EHCI Handoff. My front USB 3.0 ports aren't being recognized by Windows 10 either, and the more I'm reading, that's apparently something for which ASUS ROG motherboards are infamous. I was unsure if I could delete the
cmdline file outright, but I was able to blank it by using the
sudo tee /etc/kernel/cmdline command, and then just interrupting (Ctrl+C) that command while it hangs there.
My front 3.0 USBs still aren't working (while the 2.0s are), but the longer I've looked for solutions, the more conflicting suggestions I've found, and I think I've suffered enough for now. I'll just use the motherboard to adjust the boot order as a kind of poor man's boot loader, and keep crawling around on the floor to the back of my computer if I need access to a 3.0 USB port — because then I at least still have a (mostly) functioning computer. Thank you again!