That's how I plan to do the line lock too. Will have it on a dash mounted switch a long with 2 step and both activated by brake pedal, but only when the dash mounted switches are activated.
Either way it is done just remember to flip that switch back off. Mine activates both on the switch, LL and 2 Step Revv. If you forget to flip your switch and you are running down the track at 7K RPM then start to slow down by hitting the brakes...... That will be your wake up call! Your motor will sound like it is going to blow up and you will only have front brakes. Wreck city! LOL