For Bluetooth LE Audio device sets (e.g. pair of earbuds), bluez5-device emits "internal" nodes for each individual device, and a combine node for the device set. pipewire!1564 (merged)
Make the bluetooth monitor to create the combine nodes using module-combine-stream.
Do some shenanigans to route ObjectConfig events from bluez5-device to the correct combine node: look for combine nodes associated with device sets, and put them as managed objects of the Spa devices.