There were two minor issues I had to overcome to get this configuration as I wanted. The first was that I couldn't configure both ins and both outs to use the pulse device, as freedv insisted that the same device couldn't be used for both the radio and headset connections. I worked around this by choosing the default device for the headset in and out, and the pulse device for the radio in and out.
The final issue is that I have yet to find someone to talk to on air. I'll be using my KX3 at, I guess, 5W power.
There's a QSO Finder for FreeDV here.