Best place for line loc switch?

I will only be using it for drag racing and maybe I'm overthinking this a little too much but for doing burnouts it wouldn't be a big deal but to try and save my driveline on launches I would like to have some preload. I'm just thinking that with watching everything going on plus rookie prestaging jitters etc. that there's enough going without also have to swith of the line loc at precisely the correct time as well. I'm going to give this 2 switch system some thought, maybe I can come up with something.