

I was curious so I took a closer look at Sheltermanager and, honestly, I’m very impressed. They have a free demo on their site so you can show it off to people and see if there’s any interest.
And agree, self-hosting doesn’t sound like it would suit them or you, but you asked in an opensource thread and that is nearly always self-hosted. SM looks quite fairly priced for a hosted solution.
An example of how this didn’t work for one project. (From memory, and it was a long time ago - 2005/2008 ish)
Xchat was once the best IRC client for Windows (after Mirc). It was free software, but the developer started charging for the Windows builds of it. Linux binaries were still free, but he claimed that it was time consuming to build on Windows and etc etc (A bit rich considering it was mostly his code - and there were suspicions he made it deliberately so)
Some people were pretty pissed off about this, especially as it used some other code that was foss and it was felt against the spirit.
Anyway, it was cloned into Hexchat which is fully free on all platforms and apparently not so difficult to build binaries after all.
15 years later to today, Hexchat is thriving and Xchat has been completely dead for 15 years.