Custom Message Field for Reject / Reschedule

Please add an optional custom message field when rejecting, cancelling, or rescheduling appointments.

This would greatly improve communication for creative studios and businesses that manually review bookings before confirmation.

For example:
A client books a β€œshort” appointment, but uploads a design that would actually require a longer session.

In this situation, we usually do not want to fully reject the customer or simply ask them to choose another time slot. We mainly need a way to send a short personal message such as:

β€œThe selected appointment type may be too small for your project. Please use this link to choose a longer session.”

At the moment, it seems the only possible workaround is manually editing the global rejection/cancellation email template each time, which becomes difficult when multiple artists or admins work together in the same BookingPress installation.

A small optional custom message field during:
β€’ reject appointment
β€’ cancel appointment
β€’ reschedule appointment

would make the workflow much more flexible and customer-friendly for businesses that manually review bookings before confirmation.