On a related note, how does MAME know (and record for next time) whether or not it's the first time the selected game is being run? It may be easier to attack this problem from that end (ie. create some batch file that marks every game as having been run already).
It's very easy:
If config file (
gamename) does not exist, show okay screen (otherwise don't)
That's it. So just copy all the files in the cfg folder from the old version to the new, and you won't get the okay screen. Of course, if any changes in that game's cfg file is made between versions, you'll probably get some sunny bug.
IMO, left-right is far too easy to worry about trying to skip it, even though I compile instead of download a binary. OTOH, I don't hold game parties with people who don't know mame (or try to make money on mame based cabs, not that anyone here does), so I don't have worry about others not knowing how to left-right. [shrug]