MSD 6AL-2/ two step hook up

Good surveying question and I was just searching here for opinions myself. I am running a Mallory ignition with a programmable 2 Step. I have a manual valve body and a Cheetah shifter. The Cheetah has a momentary switch built into the lowered left side of the shifter that I am considering to use as a dual purpose momentary switch. This would allow me to simultaneously activate the line lock and 1st step when holding the button in. When released I'd be activating the 2nd RPM step and releasing the line lock. Both devices are triggered with 12v. Seems simple and the switch location is convenient to reach with my thumb while holding the shifter. I have a red indicator light to add on the dash. My second thought on this set up is,. Could I use this when staging? Not sure if my front brakes alone would hold the car but I'll test it out and see.