Neil: Did your insurance premium go up when you informed them?
I changed insurance Co and got it cheaper 
I am with Zurich. They did not even ask me if I had any mods on the car!
I will give them a call Tues. If they don't agree or increase the premium unnecessarily, I'll have to threaten them with cancellation (I know it won't work).
I do want to re-map, but only after 2000 miles.