Never mind – I got it working! FreePieBridge and FreePie simply needed to be running on the same PC as RiftCat and Driver4VR (Computer #2). I made the mistake of running FreePieBridge & FreePie on the remote PC (Computer #1) with PSMoveService.
Obvious mistake for those who know how FreePieBridge and FreePie work under the hood, but not so obvious for the rest of us who are new.
Greg, can you add a toggle option (check box?) in Driver4VR to disable the automatic launching of a local instance of PSMoveService for those of us who are running PSMoveService on a remote pc? It’s an annoyance 🙂