Okay I finally got around to setting MameWah up to use the IPAC files. (Real Life gave me a detour.) Anyway here's a few things I noticed:
The above senario worked for the most part. When I launched PCGame1 it programmed the IPAC and then when launching a MAME game it programmed it back. However if I launched PCGame2 after launching PCGame1, it would not program it back.
After thinking about it some it's like another level is needed (a system, front-end, or "MameWah" level).
Currently there is a game level (IPC named the same as the rom/LNK file), and an emulator level (IPC named same as emulator name), but we probably need a MAMEWAH.IPC (which in my case would be the same as MAME.IPC, and then I wouldn't use MAME.IPC).
In other words, when launching a game, MameWah would first look for a game level IPC, then an emulator IPC, then the MAMEWAH.IPC if all else fails. Then it would compare that with the last one used (if different then program).
Also, I suppose that the MAME.IPC could be the system default as well, as this would be most everyone's (if not everyone's) default config. Perhaps that's what you intended.
Further it also appears that MameWah doesn't store (on disk) the last IPC used. In the above scenario if I launched PCGame1 and then shutdown the computer, then the next time I loaded MameWah and launched a MAME game I'd still be using the IPC from PCGame1 and not MAME.IPC.
Hope that helps some. I'm also not sure also how many are using this cababilty in MameWah; maybe I'm the first.
(Side Note: I like to avoid having to reprogram the IPAC if at all possible as I know it will eventually wear out (It'll still take years to wear out, but each reprogram brings it nearer to it's demise). So I like to handle key mapping in software if I can. If my IPAC does wear out maybe I'll look into using the KeyWiz instead.)