Wow thank you again for such a detailed response. I haven't seen anyone else break this down like you have so I appreciate it.
Here is the thing about the Logitech Harmony Hub Driver: When used for a dimmer switch the buttons only control ON/OFF. The dimmer rocker in the home control section does not work when using the UUID method that you described. If I am wrong about this please correct me but I just tried this and could not get the dimmer function to work.
Edit: I just thought about this idea: What if I created the Virtual Dimmers in Smartthings and used the Hubitat Harmony Driver UUID method to control the on/off functionality in Hubitat but I also send the Smartthings Virtual Dimmer to Hubitat via Hubithings and use rules to control the dimming functionality of the endpoint device? Sorry if I am not articulating my idea very well but let me know if you understand and think that's possible.
