Is it really using MCU to control the transport in Maschine, or is it just that Maschine is made, as KK is made, to interface directly with the transport controls using, I guess, either OSC or more likely for these directly via the USB HID protocol?If you're willing to use that convoluted a workaround you might as well just do what I do with mapped buttons, which is also not ideal but at least is much simpler to implement and doesn't require Maschine and works in any host - either way it's just a pragmatic way to get stuff done till NI come up with a proper solution, whatever that will be.