Online Booking / App

There needs to be an option, as in other booking programs, to prompt clients about add-ons. Add-ons need the option of being 0 minutes. Having the 1min minimum can throw off an entire day.

Is there a facility for the client to place themselves on a waiting list via the booking portal if they cannot get an appointment with there usual team member at an ideal time for them?

I need the ability to suggest simple add-ons in online bookings. It will make for a good upsell opportunity and introduce clients to simple services they do not know existed

Clarins offer add on treatments but currently we are having to not offer them as bookable online as customers try to book those on their own due to the low value then kick up a fuss with customer care when the spa manager tries to cancel/change the appointment. What we would like to do, is advertise the add ons but make them only bookable if a full length treatment is booked. Can this function be made possible, so I can set these up in the settings to only be booked with...treatment 1 treatment 2 treatment 3 etc...