How to put mpe messages together?

I'm having trouble putting all the separate elements and examples of MIDI / MPE together.

I want to have a maximum of 4 voice numbers.

I also want to be able to send to Slide, AfterTouch, and Pitchbend.

I know the poly object can index notes, but i don't see a way for mpeformat or midiformat to receive an index, unless the right inlet of midiformat is for this? Although thats called "midi channel"

I thought this is where poly~ would be useful, since it seems like polymidiin handles a lot of that, but multiple forum posts say it's not necessary. ( here , here )

So I'm using a poly to index, then a [route 1 2 3 4], to direct to the mpeformats "note channel" (assuming same thing as "voice number". ) but poly was giving my note-offs a different index than the note-ons depending on where in the network i put it.

Either way, this seems to work, but i don't think its very scalable. Is there a better way to execute such a thing?