[App] MIDI to MML + Custom RS3extool2

I'm not entirely sure what the whole ROM patching feature is for as I'm not very familiar with this version of the utility, other than maybe making the setting up of the MML file slightly easier, but what you really just need to do is once you have your MML file ready to import into a Romancing Saga 3 1.1 non-headered ROM, you just use the RS3ExTool and...

step 1) load the Romancing Saga 3 ROM for the 'Load SMC' very first one.
step 2) load the MML file for the 'Load MML' one.
step 3) select the location for where you want the song data to be put in the RS3 ROM.
step 4) click the 'import' tab at the bottom, and supposing there are no errors your song data will now be at whatever location you specified in whatever RS3 ROM you loaded.

Once these four steps are done you can then go into the RS3 ROM and retrieve the song data by use of a hex editor, and inject it on over into your FF6 ROM if that's the goal, either over a current song or somewhere else and change the song pointer etc.