Thanks, will give that try.
Oddly, I put in a PS1 disk and used "Create ISO" in multiman and it too created it as a BIN and CUE file.
ISO is actually the inferior format, as the name says it's supposed to be a single ISO9660 data track...
BIN can be a full disc image, or a single track image; in either case, error correction (where applicable) is included (but not subchannels); CUE files complement them by telling how to assemble multiple tracks into the full disc or where the full disc should be split into tracks.
To make the whole deal more annoying, not all software that dumps CUEs gets the exact track positions right! And yes, at least one PS1 game cares
I don't know if Multiman uses single or split .bin; most likely it's the combined one
(although in practice, ISO and BIN naming is often interchanged)
Therefore it's not really practical to call out a single "best format" on the basis of file extensions, as the cue file can point to anything to be the actual data
(if you really want to know, the most accurate is CloneCD IMG + CUE + SUB - where the img is a whole-disc BIN under a different name.....)
In general, CD game consoles push the CD format to its limits (mode 1 data tracks, mode 2 audio tracks, XA mode 2 form 1 data tracks that can be mixed with mode 2 form 2 data tracks without error correction optimized for streaming, all possibly used on the same disc... luckily the PS1 doesn't support multisession

)
Of course, some PS1 games don't use streaming CDDA audio nor subchannel copy protection (is that even emulated by running-on-PS3 PS1 backup loaders? at least most of those games have cracks available), so the single data track may well be enough
