Other then legacy and uefi does it have a CSM compatibility support mode? An option to enable usb initialisation before bios? Eg wait for usb initialisation?
Some “boot faster” options kind of reorder boot initialisation to a point where it’s not holding the system back.
Though I’m really running out of suggestions… I can imagine you’re pretty frustrated. I know my Dell laptop was a pain to get the right settings to get usb to boot and the stupid 100db beep to silent on boot interruption.
I spent like 20 minutes self hosting and running over tailscale so traffic is always private… Never had an issue. I’ve got over 20 devices accessible on it.
Easy to remote register over ssh just by sending the installer plus running with server name plus key, then setting a static password.
I still think gaming wide moonlight is great though. You won’t really regret that.