Yes, I have done this, and it's brilliant. Much more convenient.
I had the dash switch all rigged up and connected to a Synergy2a and was very happy with it performance wise. I was on setting number 8.
Only drawback was having to stop the engine to change from the power mode to the lowest setting for economy mode. That was a change from 8 to 6. So for all intents and puposes I had to decide what setting I wanted for the entire journey.
The switch remains the same - only the box itself needs to be returned to Ron, and its a fast turn around - return post it must have been. Came back marked Synergy 2a+
Now all I have to do is lift off the accelerator pedal, flick the switch, and then back on the pedal again.
I use the new, improved 'eco' setting on motorways and dual-carriageways, and change to 'power' mode for the fun twisty bits.

Still set on number 8, never have to touch the box itself of course.
Well worth the money, IMHO.
Hope this helps you decide, but for me it's a 'no-brainer' - I wouldn't be without it.
Singvogel.
