I think the current system is just fine, I really don't even think you should be able to stop the repairing process,well you can but if you do stop it then you lose the repair kit..
In my opinion the current system works perfectly fine, It allows heavy tanks to be delt with a lot easier while repairing...Imagine a KT repairing almost full health 30 seconds left on the repair kit and then it stops repairing as soon as it sees you coming
i could imagine how that could get annoying.
