SGT-
Thanks for your helpful reply.

Took me quite a while to find time to work on this, but I just wrapped up tonight & am running a backup of my cab hard drive overnight tonight.
I'm already a follower of your ways, though--I already have my mame (virgin).xml file & my mame (bonus).xml file, which I merge into mame.xml.
Same for controls.ini & history.dat.
I've ended up morphing things a bit from how you/I used to have bonus non-MAME items (in my case, DAPHNE games, spinner hack games, & 3D art games...and someday, PC games). Because I never got MaLa to automatically fill out the file path for a game in MaLa GameList, I stopped using the rom path to filter the DAPHNE games from the rest...and I've deleted my dummy ROMs from that alternate (DAPHNE) directory.
My mame.cmd file is now pretty much a giant list of if/then statements. Works great.
I still have to go through the somewhat cumbersome route of deleting a game from my gamelist & adding it back in from the All Games list after I've done my updates in the Main Game List & refreshed it.
Something that vexed me for some time was that MaLa didn't seem to be actually refreshing games in the Main Game List unless I removed the game from the list & then did the refresh. That took a few tries to figure out.
Also, my brackets of choice (purely for style reasons) are < & > if I need something paranthetical in a game name in the list. A little digging found that the html codes for those characters are < and > , which I've simply put into the mame (bonus).xml files so that I don't have to keep going into GameList & customizing the names.
Anyway, I think I'm all set--I also no longer need to hijack those Mahjong ROMs--it's all swell.
Thanks for you help!
-Jason