This was clear for me. I've meant a (supposed) internal system area config parameter kept thru consecutive fw updates as long as there is no factory reset.
As for the PW3, I mixed it up with the problem of no longer being able to perform the factory image downgrade. You're right: Active Documents should work with 7th generation Kindles smoothly even with the latest fw. Sorry - was in a hurry...
Gesendet von meinem Google Pixel mit Yabba-Dabba-Talk.