Me too! I would like users to be able to see the number of people on the waiting list so they would know if it is worthwhile joining the waiting list. If there is a capacity of 60 and 40 are waiting, that is useful information for the person trying to register.
OK. I will see if I can support it in next release. It could affect performance (make the page slower because it has to query database to get the data), so maybe I will see if I can make it as override so that you can use it if you want
Or, it could be a button that says "Show # of reservations", with a help text to explain they could see how many other reservations are outstanding, with the caveat that they might still get a place even if it seems to be a lot of reservations ahead of them.
The button would mean no database query unless requested, and also means the query won't be repeated multiple times if the user does something to refresh the page, etc.