multiple bookings for one time slot?

If the capability is not there, this would be very useful for me:
The ability to have a capacity for a timeslot or service. I have a client who does private lessons and group lessons, so to book for the group lesson, multiple users would need to book the same time.

If you allowed group bookings, this would additionally be nice if one user could book a guest as well (always nice to be able to add a child or spouse), like you do in Event Booking. I think that extension is very nicely done.

as I have gone back through the features, I see that "number of slots" is a feature!