If you are up for some leg work, the following outlines how I have it working by controlling a device and all my keypads get updated correctly.
1) Create your scene as normal with the "master" device as the controller. (LIving Room Lights)
2) Create another scene, all everything but the "master" device as responders to this scene (include your keypad buttons unless it is the controller). (Fix - Living Room Lights)
3) Create a program.
a. If Status 'Master Device' is not on, Then Set Scene 'Fix - Living Room Lights' On
b. Else Set Scene 'Fix - Living room Lights' Off
Do this triple combo for every device you want to have "dimmable" and control with multiple isteon devices.
What it does:
Assuming everything is off, Echo will send Isy the command to turn on a light. Isy will send the command to the device. The device will respond and the Isy program will see the device is not off, and thus will run the program. The program will then turn "On" the fix scene, which will set the "status" of all the other normal responders. You can then go to one of those other "responders" and turn the light off, which since it is part of the original scene, will control the master and things will work.
I currently use this for 12 things and will probably expand it out as I go along. It is sad there isn't a scene level dim option, nor is there any facilities in Isy to "fake it" like I did the with this trilogy of configuration.
Disclaimer. This process might have been mentioned before. I am not certain if I am original in my configuration here. Also, there may be some functionality, such as the brightness of the secondary keypad linc buttons or something, I dunno. It works for me.