I use the flash to pass button as the nitrous button, push button second stage boost, or scramble/increase boost button on turbo bikes with ams1000 whenever I can. Horn for air shifter.
The pass button is directly wired to the high beam switch. about half way between the control and the wire harness conector the pass button wire is soldered to the high beam wire. So if you tried taping in on the main harness side after the conector whatever you are controlling would be activated if the high beams were turned on. I cut the pass button wire where it is soldered to the high beam wire and attach whatever I want to activate their.
I use the dsm lower button on gen 2 busas for nitrous activation with ecu editor.