geez louise. finally unlocked the dumb bootloader by using a partedmagic bootable linux usb to just run the linux fastboot.

problem seems to be windows 10 can't (in my case, or on rm's laptop) see the connected device when it's in fastboot mode. it is super fun to mess with esoteric USB drivers to no avail, i assure you.

ok, what is next. need to replace the recovery partition somehow, then find a rom.