This video, via Expert Sleepers, shows one way to get a Polyphonic MicroBrute – use four Arturia MicroBrute synthesizers.
The MicroBrutes are connected via MIDI to an Expert Sleepers ESX-8MD module, driven by the Expert Sleepers Silent Way software. Silent Way takes the polyphonic MIDI generated by the controller keyboard and distributes it between the MicroBrutes, so that each works as one voice of a polysynth.
This setup allows the Silent Way/ESX-8MD combination to replace a standalone polyphony distribution box.
Here’s the second part:
For more info, see the Expert Sleepers site.