See Animated Gif Here
It worked when I tried it changing from 0 to 1 saving the the ini then opening the Render dialog, this time it had a 2 on the end of the name ?
I would play around with it more.
If you can open the render dialog and send keystroke
TAB 19 (Save outfile)
spacebar (check)
TAB 6 (Save changes and close)
spacebar (enter)
will save that and then render without restart.
Once you hit the Save changes and close button even with outfile unchecked it will save "autosaveonrender2=0" then if you change that manually it will be checked when you open the render dialog again.