I have a batch file for loading MAME from MaLa. Once of the advantages of this is that you can define options, for instance, for using another version of MAME for certain games. I also have defined App1 so as to be able to manually launch a game from MaLa with a specific key.
My idea is to implement an option that detects when MAME fails to start a game, for instance, because of roms outdated or because they are broken in the current build, and then the frontend automatically resorts to App1, trying to run the game with the alternative version of MAME.