Yesterday, I tried Synchron Pianos on M1 MacBook Pro.
elicenser worked without problems.
Installing and starting Synchron Pianos was no problem either.
But first, with macOS 12.2.0, I couldn't select USB-MIDI in Synchron Piano Preferences while USB-MIDI worked well with other software such as garage band.
After updating macOS to 12.2.1 this bug immediately disappeared. Unfortunately, the update broke my external aufio interface (Behringer XR-18).
Using the internal audio instead, I felt there is a small latency that wasn't there with Intel, just as WilliamMcVey has reported.
Let's see what further updates will bring...