These settings worked for me. Note that there is a rare hiccup that makes the Pocket Operator play temporarily at double speed. If necessary, you can turn the metronome on/off with Function + Cue iirc. Below is directly from my notes to myself, so I hope they make sense:
Using OT metronome to sync PO-12 and Volcas.
With OT sequencer stopped, press play on connected device, then
Audio = Cue Out to Sync In
Project > Control > Metronome settings
Active = On
Main Volume = 0
Monotribe: Sig = 4/8 Cue Vol. = 32
PO-14: Sig = 1/8 Cue Vol. = 127 Key-oo + BPM = SYNC02
I think this is the post you’re referring to: