Any way to stop the game from automatically creating .mas files?

It's extremely annoying because it won't let me edit or delete them.

 

What .mas are you referring to?
Where and when are those .mas files being created?

 

Sorry, I should've been more specific lol
When skinning, the game creates a .mas file for the skin automatically now. This is because of the new painting system.
It is a bit annoying because, for some reason, I can't edit these .mas files to make small tweaks on the livery.
I feel kinda dumb though, because all I had to do was not editing the materials before finishing the skin.

 

If you do make changes to the skin, when you press "Reload" it updates the .mas file anyway regardless of whether you have a region or not. (well it does for me anyway)