Hi hofer,
Thanks for the request. It’s unlikely we will add in the ability to set an end time for a reservation, especially not in a way that a customer can select that on the front end. This plugin is created with restaurants in mind, and, for that, it makes more sense to do something like set an expected dining block length and apply your restrictions based on that, rather than having people manually deciding, at the time of booking, how long they want to be there, or even expecting people to know that.
For your use case, it sounds like you might be better served using more of an appointment booking type solution (e.g. https://www.ads-software.com/plugins/ultimate-appointment-scheduling/), which is more global and not targeted at restaurant reservations, and with which you can create different services offered that each have a different duration, provider, location, etc., and for which the calendar automatically updates these elements based on the chosen service, etc.
