Yes… bios mod is risky and we all take chances, so take it or NOT, if you care for the current state of your asset don’t proceed then… and don’t ask for any assurance of free risk operations with mod files, unless got a confirmation of a user with same mod file flashed, even then its never risk free.
NE for extraction, regular for operations, so your assumptions are correct.
Structure is different but GUID id is present as also DXE drivers volume.
Wait for other users POV, good luck.