In a VG sense it works no problem, but under normal P&P RPG it wouldn't for the most part aside from an aesthetic representation. As you said it would force doors to be 3 squares wide , if an encounter in 4e has doors like that you entered it would create movement issues due to squares being representative of 5 feet. I mean using half a move action to enter through a door is kinda bizarre and won't work. This is just one argument against mind you.