Oh cool, finally something's happening!
First, my setup: MacBook Pro Max M1, iPad Pro 10.5,
and iPhone 15 Pro Max. Switching between songs works well and quickly.
What I'm still missing, though, is a play and stop button.
As for the visual metronome, it only works to a limited extent.
On the iPhone, the metronome is about 1ms faster than the metronome
on the MacBook. On the iPad, the metronome is synchronized,
but only if you wait about 4 seconds after switching
to the next song and pressing the play button. Thanks.