Staff Member pre-selection

When an appointment share code looks like:
.../book-appointment/?s_id=2&sm_id=15&allow_modify=0
this pre-selects a service with id 2 and staff member with id 15.

What would be great is enabling Staff member pre-selected, so that
.../book-appointment/?sm_id=15&allow_modify=0
selects already the staff member with id 15, and the form continues with the selection of the services associated to this staff member. (The custom booking form sequence eventually set with staff member first and then service).

Currently, this works half way. The staff member will be selected, but all the services in the system will be shown with default values.

I am marking it as a bug, even though the documentation doesn't indicate this use case. manipulating the URL params, can lead to booking with the wrong price with the wrong staff member. And that's something a user can perform.