Would make engis never have to be with their buildings. Think Rescue ranger + This. Repair from a far. Sappers removed from afar.

No just no THis would encourage the strat i will call "The Lazy Engi" When the rescue ranger came out it sort of encouraged it because of pick up sentry from afar or heal from afar and its decent and the main downside was you couldn't get rid of sappers so a engi had to be near action still but this would just let him stand away from battle be near despencer and heal sentry and stop sappers from the safety of his confort zone... and althought people say "its so annoying when a spy saps a sentry since you have to kill him then get rid of sapper"... well if it was so easy to get rid of a sapper then what would be the point in one existing to be honest.