I agree that if it's an extremely close play at the blue line the offside challenges should stop. Although I will admit if the Leafs allow a goal under those circumstances, and it's disallowed because of a close offside, I won't complain if that happened.
Personally, I think the NHL should go with an idea Ray Ferraro once said about this rule. If a goal is scored on a play that might have been offside and a head coach wants to challenge it, they should also see if any of the players on the team who allowed the goal had the puck on their stick with a chance to clear it. He equated it to when a team touches the puck on a delayed penalty call, because when that happens the whistle is blown and the play is stopped. So, if the puck was on the stick of a player that was their chance to clear it and if they failed, they shouldn't be saved by an offside which might have happened 30 seconds earlier.