I can confirm the harpoon works now, however, you failed to mention that it needs a firmware update from a windows based iCUE before working on mac :p:. Otherwise yeah great to have my mouse working!
This is somewhat of an old post but I'm running Mojave with a Harpoon RGB mouse and the iCUE isn't detecting it. I have given the iCUE the right to control the computer in the system preferences and have tried rebooting after installation and it still doesn't work. Any clues?