Bypass kits are used to be available or you could make your own. I have a TPO one on my S4 for many years now and it works great. You can run the engine in neutral with the stand down but otherwise it still cuts out.
I found this for 2000-02 bikes:-
http://www.electraeon.com/sidestandbypass.html
I'm sure there are others.
__________________
Roast Beef Monster!
Termignoni and Bucci - Italian for pipe and slippers!
S4 Fogarty, S4R 07T, 748, Series 1 Mirage