Midi Export with separate channel per voice MS4.3.1

I'm creating a barbershop score, and would like each voice to export to a separate file (or at least channel).

This is the most recent discussion I can find https://musescore.org/en/node/329766

I'm sure this worked in 3.6 because I don't remember ever having to use a workaround before.

Current process:

• Create barbershop score
• There are two parts created, one for each stave. I duplicate those, and set visible voices so that Tenor (voice 1), Lead (voice 2), Bari (voice 1), Bass (voice 2) are the only ones visible in each part
• Export midi, or even mp3. Each file contains both voices, even the ones I have hidden.

The only workaround I have is to create separate staves and explode the tracks, but this means creating a separate score just for export, which is a PITA