Honestly this is my go to source when I can't figure something out, even with some non programming AutoCAD issues and almost always before turning to Autodesk....why? Because I get a more accurate answer here and in substantially less time than asking elsewhere.
As for a hosted forum, this one looks very promising:
https://proboards.com/It seems to have very good reviews, so it might be something to consider.
As near as I can tell, there are three options with them:
- Completely Free
- $15 a year allows you to use your own domain name with them
- Additional Business features and remove ads for $50 per month.
All of the options appear to offer unlimited forums and users.
They will also offer some incentives to move forums with more than 50 registered users:
https://proboards.com/switch-to-proboards-free-forumsI am not sure what your current costs run, but these seem like reasonable prices to me. I mean given the number of users on this forum, it would amount to very little per user to cover the $50 a month if those features were important. I am unclear if the $50 option includes using your own domain or not, so that might be another $15 a year, but not too bad.