I have now read more on Discourse and have discovered that it's more of a full blown Nabble than a single forum for a single administrator. The costs are quite high if you want to run your forum on their server, and it takes the same kind of high end hosting facilities as Nabble (Ubuntu 16.04 LTS server, Postgres 13+, Redis 6+ and Ruby 2.7) to get it running, al though the install process itself is reported to be fairly simple thanks to using "Docker" as an installation tool.
It's over the top for my needs as someone who runs low traffic forums and blogs, with users numbering in the low hundreds at most, many of whom only post once or twice then disappear.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.