In this method, the Midronome's analog clock output is brought into Reaper as an audio click track during performance; the click track is subsequently transformed into a series of tempo markers, create a varying tempo envelope track on top of which further overdubs can then be made.
One of the main drawbacks of this is that it consumes an entire channel of the audio interface just for click, and on smaller interfaces with only two analog inputs like the Yamaha Steinberg UR22, that precludes simultaneously recording the synthesizer output or other audio in stereo.
It would be great if the Midronome could somehow send those audio clicks over its own USB connection instead, freeing up that channel on the interface, but as Simon notes on another somewhat related thread,
However, for the purposes of generating the click pulses as audio inside Reaper, it would be sufficient if the Midronome's analog clock output optionally also generated MIDI note messages, e.g. tapping middle C (note 60) for downbeats, C' (note 68) for other beats. Then in Reaper, the Midronome's USB MIDI device could be routed to a track with a simple virtual instrument (e.g. ReaSynth) on it to make the click audio.The only idea I potentially have would be to make the Midronome an audio interface and send the sync signal as digital audio over the USB - that would be tight enough. But that would require DAWs to handle two audio interfaces (AFAIK none do today), or a plugin able to send data to another audio inteface than the main one, or an external software able to "redirect" some of the audio to another interface)
It would be nice to be able to turn it on and off, and to configure the note numbers of the down/other beats, the MIDI channel to send them on, and the length of the note (between note-on and note-off).
But even if all these were hardcoded to some arbitrary values (say, notes 36 and 38 on channel 10, one tick or 10 msec in length) that would be perfectly fine. In fact, even if it were always on, always sending metronome notes over USB, I think that wouldn't be a problem either because those select few DAWs that can consume the MIDI clock and start/stop coming in over USB aren't to my knowledge doing anything with note messages on that stream.
There's probably also a use case for (as an optional configuration) sending metronome-as-MIDI-notes out over the DIN jacks as well. I can imagine wanting to drive a GM module or other hardware device to generate a more musically inconspicuous drum sound for playing along to.
It's a secret project which I cannot mention yet. Let's see when this comes out (hoping it does come out!).