I think part of this also turns on the extent to which the board is a “service”. There is a checking process to determine whether it would apply to us, which should be the first port of call - unless someone has done it already.
It says: “If your business provides an online service (a service made available over the internet), such as a website or an app, the Act may apply.” That might suggest a way to get around it. I can see why the other forum was scared by the broad scope but I see this as being aimed at sites that have a direct link with the public by virtue of the services it offers. Could be wrong though.
Edit: Plus what Hugo said about risk assessments.