Not only does the Beat Buddy play MIDI drums, it will play any MIDI in your song parts. This means you can hook up your MIDI patch lead and trigger things.
So I created a song intro which simply plays MIDI Note 1 (C#) at the start and after 2 measures plays it again. Then in OnSong, I created a MIDI trigger to toggle the metronome on this note.
Thus when I play a gig, I can get a count in that plays through my iPad (in OnSong) and only I can hear it.
Pro tip: OnSong can sync with including broadcasting the metronome. So if you’re in a duo or small band, everyone else can get that metronome count in too (However in testing, it can be a bit delayed).