How much support fits in one reserved hour?
That's really hard to say, as each question is different.
For standard questions, about using common extras or core features, we can typically answer right away without having to do much additional research into the specific topic. Depending on the complexity of the question and how much detail you'd like in our responses, we can typically fit around 4 of those in a single hour.
For other questions it may take us a little longer. Perhaps we need to research the extra a little first, login to the site in question to do some debugging, or examine code in detail before we can get back to you. In such cases a single question or problem may take up 30-60 minutes.