Hello! I found this topic based on this, so thank you 
I am looking to use my forum in basically the same way. It’s a public forum, but there’s a category (and sub-categories) that is private for people that are in an online course/subscription that is hosted on my site proper.
This use of the invite link system seems to work for my needs, but in theory, I will run into the issue of the maximum number of usages/redemptions.
Has there been any movement on no longer having a max number of redemptions @tobiaseigen @dan?