To be honest, I was about to rebuild the HEAD OVER HEELS ROMs with the generic builder... but if it works as is, then there's no point!
Have 4x |4K demos, instead!
But feel free to rebuild it, as you can read in the original post was a test during thefirst days of the megaflash, nowdays i would make very different.
For example, i would make something similar to WHDLOAD, having a game launcher rom and putting the games in roms that can not be initialized, then in this launcher rom is stored a list that is showed at start and you can choose with Cursors and Enter the game to launch. Then add a patch at each game for you can return to the launcher and as the launcher rom is practically empty, you can storage there the game hiscores in a similar way like a PSX memory card works

And of course, define an standard for everyone can use it.