Or marked so that staff know when merging or changing things to retain THAT email address rather than others.

Right now we are using logic to determine which appt was booked by client self-booking and then determining which email address is part of the account used for that booking. But in many instances when merging clients we end up taking a gamble or asking the clients. If the email that is being used to actively book was specified to staff (perhaps also locked so we can't change it since it has actually been verified), then we would avoid some errors and also adding useful information. Staff should be able to discern which clients have online booking accounts set up so we can customize our verbiage for those clients rather than telling all clients that they can book online when some already very much do.

Also curious if two profiles are merged and the one that's email address has been deprecated, what happens if that deprecated one was the one the clients were using to login to their booking profiles, do they lose their account or do their logins still work with the now deprecated email. Then also do receipts default to the staff viewable email or the client login email that we deprecated?