Just finished receiver #2.

This one comes with an Icom RC12 remote.

I figured out a way to use the "Speech" button on the RC12 to strobe the ADSP2's control line, thus giving me the ability to remotely control the filter bandwidths as well. One must use an optoisolator; connect its output switching in parallel with the panel-mounted "Speech" push-button and tie the input to the orange/green lines which were previously removed from the switch.

I have to order a couple of these devices in order to construct the circuit but theoretically it'll work.