Apollo's ult Itani Lo Sahn will just go through frozen shelter, Venators ult Ira Domini will just go through frozen shelter, and if you can frozen shelter on any player near its range limit, they are extremely likely to just walk through its wall (teamate or enemy)
you should be able to cancel the abilities by both pressing the key again and pressing the cancel ability key: all three of kelvins are long channels that you don't have to worry about accidentally double pressing to cancel. and often need to be canceled at a moments notice