Yes, because unless the flash is stored externally you cannot flash "back to stock" with any flash that is inside the ECU. What I mean by that is that you can flash your mappings back to stock mappings sure, but because all that other code is still in your ECU if a dealer runs a CVN check in
PIWIS your ECU will show up as modified even if you have the stock maps loaded. I'll have to go check Keith's statements on the adjustment range but it is my understanding that you can create a map that goes all the way up to say 103 octane and the ECU will adjust whether you have 91 octane, 95, 100 or 103. I guess it depends on what you are looking for in terms of "stock" and "modified" then.
I just read Keith's statements and what I understand him to say is that you want a map for close to the octane that you put into your car and then let the adaption channels work from there. While I agree that does sound optimal I'm wondering why some ECU tuning designed for 100 octane doesn't seem to have a problem with 91 octane, meaning no pinging, still good power, etc?
APR sent me their cable and flash awhile back but I haven't had a chance to test it yet because of other things that came up with my car, hopefully when I am back from parade I can do some testing, too much to do, too little time...