I not sure you understand how synth rack automation works, it uses VST automation so is subject to the rules of having the R and W buttons selected correctly. Also you can choose where the automation appears. I've never seen one control affecting more than one synth because there's a direct mapping between the synth knob you turn and the synth with which it's associated.
 
It's a pretty deep topic and I would recommend checking out the help, I don't have the time right now to explain it in depth. The key is not to apply "standard automation thinking" to Synth Rack controls; after doing the automation, unfold the automation lanes to see what happened.
 
The subject in general would probably make a good "Friday's Tip of the Week," though, or fodder for my Sound on Sound column. This is one of those situations where at least for me, the time invested in learning how to use this feature has paid off.

Anderton
I not sure you understand how synth rack automation works, it uses VST automation so is subject to the rules of having the R and W buttons selected correctly. Also you can choose where the automation appears. I've never seen one control affecting more than one synth because there's a direct mapping between the synth knob you turn and the synth with which it's associated.
 
It's a pretty deep topic and I would recommend checking out the help, I don't have the time right now to explain it in depth. The key is not to apply "standard automation thinking" to Synth Rack controls; after doing the automation, unfold the automation lanes to see what happened.
 
The subject in general would probably make a good "Friday's Tip of the Week," though, or fodder for my Sound on Sound column. This is one of those situations where at least for me, the time invested in learning how to use this feature has paid off.

Thanks for attempting to explain.  I think a Friday tip on this topic would be cool.  I feel the documentation is not that great in this area.   

For me, one knob is controlling all the knobs you see turning here:
 
https://youtu.be/JoNkyonZllo
 
I am using the came knob for those settings as I dont have many knobs, BUT i feel it should only control the synth I am actively playing, kinda like when you do standard MIDI Learn functions inside a VST softsynth.  It doesn't effect other synths in the project.
 
 

For my two cents, I'll say that the new synth rack is a big plus, there's better choices for docking. I recently started playing around with synth automation, it's quite powerful. You can do some wild things, like grouping an output control to a fader and make your own gain rider.