CueAir · Monitor-only click
Short answer
updated
A MacBook or phone can be the source, provided the actual mixer and audio hardware support the connection. Audio does not travel through CueAir. Use Mac USB audio through the mixer/interface, or a phone headphone/line output into suitable mixer inputs.
The path is metronome source → dedicated input → each musician's monitor bus → physical output. Keep it out of audience LR and any audience M/C path. CueAir controls the mixer's part of this path.
X32 example only: CH 31 and buses 1, 3, and 5 are placeholders, not known empty or safe destinations. Check the actual sound in a rehearsal.