I also have a Kenwood + ADS-MRR setup. Finally got all the buttons programmed and working. For using Bluetooth buttons with aftermarket radio, I just wanted to point out my mistake at first so no one else has to go through it again:
2013 Civic HF, base audio with Bluetooth. I think this also applies to LX.
Kenwood DDX9906XR
When programming the Maestro RR, be sure to
uncheck Bluetooth, during the step of "SELECT HOW YOU WANT TO CONFIGURE YOUR SYSTEM". This is where I got wrong the first time. I kept the Bluetooth checked following my intuition because of course I DO want to use Bluetooth (and the buttons), but I didn't realize that refers to factory Bluetooth module, not the one with the aftermarket radio, nor the Bluetooth buttons.
When wiring up everything, follow the "CIVIC
WITHOUT AMP(for base stock radio)
NOT RETAINING OEM BLUETOOTH(for using the BT buttons with aftermarket radio) 2012-2013" procedures, specifically,
unplug the factory BT module and connect the orange/red wire to pin 15 of the unplugged factory Bluetooth module harness. The instruction has the pin number diagram of the connector (if I remember it correctly the direction was looking from the wire side).