Editing Custom Fields in Appointment+

I noticed I'm unable to edit custom fields from the admin panel. Is this a bug ?

I also noticed that manual adding a new appoinment in the admin does not show the custom fields. Is this a bug too ?

Both of them are critical for my application, as one of the custom field is a tax number which must be inserted/edited for all my apointments.

Thanks in advance for your help

Kind regards