Ive had mine restricted properly through FI, I had the washers fitted by Honda, however they have not re-jetted it so it runs like a bag of crap, it just bogs down when I full throttle it in anything other than first, I may get it jetted by them or get it done on a dyno.
I was also told my the Honda garage that they can bring your FI certificate 33 bhp through the ANPR camera system.

they would say that, they get to fleece you for money !

Ahh well it wasnt dear at all actually, I got my restrictors which I had to pay the genuine £172.99.
Then for £100 cash I got a brand new £50 battery, brand new indicator relay, stripping of all my fairings to find my electrical fault and then fitting of the restrictors :)