they ussually login to the phone, just like the computer at the station. they need to login to use it. there is no Guest user on the machines.
I get what you are saying. why dont u make a regular seat, and assign that that phone with two identities, one with hotdesk and one with regular user, assign one line key for the regular user and the other for hotdesk? use the same regular user for all the hotdesks.