Reverting

Just like flashing, reverting back to an original Asus firmware is just as simple as flashing with a firmware downloaded from their website. The same rules apply as when flashing Asuswrt-Merlin: resetting settings might be required if going back to 32 KB nvram or to a much older or newer firmware, etc...

There is no special procedure required. For instance, Asus does not prevents flashing an older version of a firmware.