Gentlemen:

I too had my grips wired for speed brakes but found it very easy to accidently hit the switch on the right side of the coolie hat (used for trim) and accidently deploy the brakes.

What I have done is put an "Arming switch" in the panel so that upon clearence to decend I can enable power to the brakes and then activate them via the grip.

Just a thought..

Dave