Hi @george1 ,
You have performed good research!
On the Zigbee protocol, a useful specification is this: https://zigbeealliance.org/wp-content/uploads/2019/12/07-5123-06-zigbee-cluster-library-specification.pdf
I am using this :
https://www.amazon.com/Sniffer-Protocol-Wireless-Interface-Antenna/dp/B09C8J9GXK
You can look at this driver code. The dimming mode of the Tuya switch is hidden, as it is not usable at the moment in HE. If you enable the debug mode in the code (change the line @ Field static final Boolean debug = true), you can use the switchMode() command to put the device into a dimmer mode. Make sure you wake up the device (press button 1) while sending the switch into dimmer mode command.
What prevents it working in Hubitat is this. A Wireshark screenshot showing what is the TS004F device broadcasting in dimmer mode is here.
A possible solution could be to configure both the Tuya TS004F dimmer and the bulbs in one and the same Zigbee group. The HE hub will not receive the dimmer group broadcast commands (as these are filtered in HE), but the ZIgbee bulb will and will ramp up/down its brightness. I don't know if the bulb will send the brightness level back to HE or if it will need to be polled.
A similar solution was done for SmartThings, as they do not filter the inbound Zigbee group messages:
