There is a group on groups.io for HDSDR: https://groups.io/g/hdsdr If you’re not a registered user of groups.io you’d have to become one.
I have not tried the RSP1 I have as a standalone on HDSDR but I will do so. I have tried the above setup now with SDRUno, and I am unable to click and tune anywhere in the spectrum window. However I can scroll the wheel on the mouse and do so. No idea why that would be. This setup is also configured with Omni-Rig and there is full control over the radio’s frequency and mode. Just no point/click/tune whatsoever.