Anyone who wants to play with this Homebridge plugin, here are the instructions.
On your coordinator, go to the HubConnect Server App and add a new Hub.
Remember your connection key, you need it later and enable "Send mode changes to Client Hub" and "Receive mode changes from Client Hub"
On you Homebridge server, run the following command:
npm -g install homebridge-hubitat-hubconnect
Edit your config.json to add a new platform:
and restart Homebridge. Once restarted, you can go back into your Homebridge Hub Instance on Hubitat and select the devices you want to have available under "Connect local devices to Client Hub"
You still need to restart your Homebridge server once after you selected the devices that you want to have available or make any changes to that selection in the future.
The "old" Homebridge App for Hubitat is not required anymore with this setup
The README for the plug-in can be found here: homebridge-hubitat-hubconnect/README.md at master · danTapps/homebridge-hubitat-hubconnect · GitHub
And last but not least, I want to make sure that I thank @tonesto7 for the base work he had put into the original Homebridge integration, I just merely adjusted what he had created.