I'd like to allow invitees to choose meeting durations

Hey all. I generally love Calendly, but one missing feature bugs me. For some meeting types, I want to allow invitees to choose the duration of the meeting, within some choices I specify, sort of like this:

Calendly support suggested this:

The problem is, I already have multiple event types (Client, Prospect, Student, Client including evenings and weekends, Student extended hours etc.) If I clone all these events to allow for 45 / 60 / 90 / 120 min meetings, I will end up with an unwieldy list of way too many event types. Then if you need to edit an event, you also need to remember to edit all the various duration instances of the same meetings. It’s wildly inefficient and unruly.

Is there any reason you could see why Calendly is not letting us specify these choices for SOME meeting types?

For Calendly employees reading this: Is this feature in the works? If not, why not?