I'm not sure if this is the thing to do, but version 3.6 of s1res can extract the firmware of the 9.X.XX mp4 players ( i know, i've tried it, it also says so in the updates section of the website.)
What i'm suggesting is that when people extract their firmware using s1res, they could save a copy of it before they edit and call it 'backup' or something like that. Then they could edit to their hearts content

Please correct me if i'm wrong, i don't want someone's player to brick up because i was wrong.

Hi agree with this as well. Always good to have a backup.