Thanks for your input.
In the end, I got hold of their tech support, apparently in China. I think several individuals got on the chat. The conversation was very sparse but they sent me a document that purports to show how to get the joystick to work with MSFS. But it appears to be a beta - it’s really badly written, with no concept explanations and missing steps in the procedures (I know about this stuff, I am a technical writer by profession). Anyway, with the document, and their help, I did actually get the joystick to work. And it does appear to be very good.
The SimAppPro software still pops up every time I start my PC and - here’s something weird - if I let it run, it disables my mouse(!) But I don’t need it now so I can get around that.
Anyway, thanks again!