I found my own answer!
After trying multiple installs/uninstalls via Impulse, I went to stardock.com and downloaded the Public version, so I had a local setup file. I ran the setup manually and installed the public version, configured for secondary, and rebooted. Ran Impulse after the restart, and upgraded to the Pro edition I've paid for, and then restarted again. I now have mouse control of my secondary box again!
Not sure if the base install being done by something other than Impulse had something to do with it, but it worked for me!