Syncing Midi Clock To External Looper While Changing Patches

Hi,

I'm using Mainstage in a live looping duo and am trying to sync the beat clock to my Boomerang looper. The idea is for us to hit play on the beat clock and for the looper to quantise its loop points to the nearest quarter note. Easy enough, right?

I created an external instrument channel at the concert level, set its output to my interface's midi out and then, in the midi out tab, selected the 'start sending midi clock on patch change' option. It works, but as you'd expect every time I change patch for a different keyboard sound, the midi clock restarts - which causes the synced looper to stutter midway through playback. What's weird is that the metronome playback doesn't falter at all, just the clock information being sent. Is there a way to send midi clock continuously while patches are being switched?

Thanks!

Jack