I discovered this more by accident than anything. You can connect to at least two Bluetooth devices while using a USB connection to a computer. I don’t even remember seeing this as a feature but I’m not complaining.
When I first received my speaker, I connected it via Bluetooth to my iPhone. Later I paired it to my iPad as well. I just assumed that it was only connecting to one device at a time, and it first appeared that way as well. However, the next morning I plugged into my work computer via USB and found that both my iPhone and iPad were connected as well.
Hello @mdu
Welcome to Poly Community !!
Sync 20 is multipoint compatible and you can connect two mobile phones or one mobile phone and one BT600 at the same time via Bluetooth.