I am not sure about the latest version of mame, I think I am running .112, but the set49mode works great.
I used mala, but it should be just as easy with mamewah. All you need to do is setup the set49mode software, I think you just point it to the controls.ini file. When you start a game it reads it and starts up. The details on the tigerheli site are great.
And if you want to, somewhere on this forum is a GPWIZ49S.exe that does not show the joystick setting before starting a game. Normally it shows a popup with 8way or 4 way or whatever.
The controls.ini from set .111 should be fine. I am not sure what games were added from .111 to .115 since I have not run into anything the set49mode can't handle. I guess for the games that were added you will have trouble, but since controls.ini .111 is still in use it must not cause any problems. Otherwise someone would have updated it.