This isn’t a problem, it’s just something you might want to consider one day…
If I create a 30 minute conversation, I have the option to cancel it, or change the topic, or invite some friends to join. It would be nice to have the option to extend the length to, say, 45 minutes, leaving everything else intact. As it stands I think I have to cancel the event and create a new one, and I don’t want to confuse people who have already signed up.
Likewise to change a 60 minute to a 30 minute when I already have 2 people signed up and I think that I would like to talk to just those 2.