MAME documents what exists, it's a non-issue.

If they want to go after ROM sites hosting them, they're welcome to.

The best way to completely suicide their format would be to go after the ROM sites; as they're not the copyright holders of the actual games I imagine The Internet would annihilate them. Their reputation is bad in small circles right now, those circles would expand rapidly.

Convert them to some format that works right now and hope SPS will make IPFs in the future?

I think at least one of them is.
So which format would be better suited for MAME? We're free to choose here.

Any format MAME accepts where the game boots is OK; a straight sector image is fine for things that aren't copy-protected for instance.

"Unresolved" flux dumps, where you have the raw result of reading multiple rotations of each track are annoying to handle (kryoflux, spc, edd...).

"Resolved" dumps where someone extracted one rotation starting at a fixed position (such as the index pulse, or any position that ensures inter-track synchronization is correct), computed a nice "mean" flux change position, and found where tricky things like weak, unformatted or damaged zones are present are very nice, we love them (woz, ipf, mfi...)

"Cooked" formats where sectors are extracted lose information (contents and sizes of gaps), but it can be information that doesn't really exist in the first place, on unprotected stuff in particular where the "standard" system formatting is used. We handle a billion of them (there are usually like two or three per system).

OG.