Well, I found my issue. This note in relation to Mojave still applies to Catalina:
https://www.3dconnexion.com/nc/service/ ... ojave.html.
After allowing loading of the kernel extension, I can now see both the SpaceMouse and the CADMouse in the Device pane.
Unfortunately, when I run Fusion 360 (the application that I specifically wanted to use with the SpaceMouse), the cpu usage goes straight to 100%. And if I actually try to use the application, my laptop fan fires up and it's more like 160%. And half the time I start Fusion, the SpaceMouse doesn't function. So I uninstalled the kernel extension and immediately saw my idling Fusion cpu usage go back down to <10%.
This is really unfortunate. I was so looking forward to my SpaceMouse
