Saw your post re EFI lock. I bought a 2020 13" MBP i5. It booted up, the next day I erased the internal storage & attempted to do a clean install, but the computer would not boot. I took it into the Genius bar & after some time it booted it up and entered DFU mode. Then we hit the activation lock screen. Looks like you figured out a solution. Can you provide a link to instructions?