I admit this is a very ambitious suggestion that is unlikely to be considered given the resources it would take to develop. Did you consider extending the functionality of SENA mobile application to allow intercom communication over Bluetooth between the phone and one or multiple headsets when traveling in the group with a four-wheel vehicle? Even one-way communication would be useful. You wouldn't have to worry about people using it on the motorcycle, wind noise would make it impossible to use.

Also. updating firmware over Bluetooth, using your mobile app seems like a logical next step and would make the upgrades so much easier.