I don’t know what connections the MS-20 mini has but if it doesn’t have USB, try a midi-usb adapter. I have one for my korg volca’s, works like a charm. Just shows up in Renoise as a midi device just like any other usb midi device, then in an instrument’s MIDI tab there’s an “output to” section and you just choose the adapter. And that’s it, done and done (except for returning the audio back into Renoise, but I’m assuming you have that set up already?).
As far as sequencers go, besides the normal Renoise pattern editor, there’s all kinds of sequencer tools, it even has its own tag:
My Korg has both MIDI and USB. I can connect it fine to renoise, I can use it like a MIDI controller, and I can record samples with it in renoise. None of the sequencers you included are what I am looking for.
However I figured out I can do what I’m looking to do using “phrases” in renoise.