Hm, I don't think this has anything to do with controllers -- this is all GUI widget code.

> This patch fixes only the current state.

This breaks the current state by not "tagging" the parameter set as originating from a left mouse button event.

Think of this like tagging your events. All widgets should tag their left and right click events with the fact that they came from a left or right click. Not doing so limits the selectivity available in the ```<Connection>``` block. 

Could you explain what problems this block is causing in your effort to simplify the skin.xml boilerplate?

In the future, when we support touch events in widgets we will have to replace the Left/Right variants with a generic event type you can provide with your setControlParameter calls.