Master disconnect switch on ecm cars

[ddavisart]

How are you guys dealing with a master kill switch if the car has a modern swapped engine in it where most things are running through an ecm (fuel,ignition, etc)? My first thinking was that a a kill switch to the ecm and alternator would shut the car down quickly, but the fuel trims would need relearning each time on the ecm. Not sure if that adds wear to the computer system overtime. Curious how others have set this up as I would like to set one up for my track days that I can reach from the drivers seat and also use it in the garage when I need to cut power while working on it. Thanks