I know not it’s not DIY and the tracker format is not everyone’s cup of tea/coffee, whatever…
But this looks to be a really interesting device.
Quite a few limitations if you like your polyphony, but it does have some nice workflow and performance features.
Even an FM radio that you can sample and throw into a granular synth.
It’s coming in at a good price by the looks of it too.
There’s several YouTube reviews if you want to find out more.
Above guy - Benn and Gear, records as The Flashbulb, which I highly recommend