As far as I have seen, you are absolutely correct: "Preset ROM ID number" in the manual refers to a two-byte number with the MSB as the ROM Identifier and the LSB as the bank number. When I press audition, I tend to automatically think of the MSB as the ROM ID and LSB as the bank number--just an eye to mind short-cut when doing hands on stuff. When doing anything with sysex, I think of ROM ID as LSB MSB, not SIMM + Bank.
Thanks for catching me on that!