Even after flipping through everything on the forums that says XIM Commander, it's still not perfectly clear what it's supposed to be, to be honest. It seems the basic idea is that it's a way to connect your PC to your XIM so that you can use devices that are attached to your PC. It can use your PC mouse/keyboard with a toggle button, but it can also use other stuff, so maybe things like flight sticks and rudder pedals.
For XIM4 you need a USB easy connect cable. I just grabbed one of those. Getting it running has been.. a bit of a pain. Simply opening the programs in the specified order (Manager with commander switch->XIM Commander) has only worked for me once.
Now with XIM Manager /commander mode up via USB easy connect, I don't see any of the device icons anymore:

The one time where it sort of worked there were regular looking icons for my mouse, and a USB hub. I'm pretty sure that's the case, but maybe it's possible I'm confusing it with one of the times I got regular Manager up via Bluetooth.
The little button notifications don't pop up when I press anything on my controllers either, but if I tell it to load a profile it seems to do it, as the LEDs change color on the device.
Opening XIM Commander itself just doesn't do anything, the little window never pops up. It does pop up an error if I attempt to open it with XIM4 Manager Commander Mode closed, but if it's running it just seems to silently exit on launch without a peep, never even rendering a window.
At one point when XIM Commander was sort of loading, both XIM windows would freeze and it would lock up explorer (and task manager!) in a cycle of crashing, until I finally managed to get in a click to kill XIM Commander.
I'm sure there's potential in there to do cool things, but right now this is some of the jankiest software I've ever tried to use.