Just gave it a shot. This is amazing! I'm on linux (easier drivers!) and I love that I can now use multirom again! Some suggestions I had were:
Any way you could make the multirom part work without a copy of LSDJ in the rom? It seems like most of the code is already there. I'd just like to be able to fit more stuff onto bank 2.
Absolutely. I just added it to LittleFM because it seemed natural. The plan is to eventually release a standalone menu ROM and patcher. Ideally, I want to wait until I've made a ROM which handles SRAM management properly. What I have in mind is a to store sav for games/other software in an LSDj type file system, so LSDj could share a cartridge with other thing using SRAM, and so that the standalone version will use SRAM more efficiently than current menus.
However do you really need a version without LSDj? You've still got 3 MB of free space. Do you need the extra 1 MB for other ROMs? If not I'd just put the same big multi-ROM on both "pages" so you don't have to worry about switching/being stuck on page 2.
Ability to return back to the menu via some kind of button combo? This isn't a big deal I just thought it would be cool.
I already have a way of doing this. However, this currently requires manual patching of each ROM to add a bootstrap for the return trip. I've actually already done this to a number of ROMs for testing. If you tell me which extra ROMs you want, I can prepare a ROM for you.