order of vector doesn't reset when input changed

This is a bit difficult to explain but I'll try: In some cases there doesn't seem to be a way to change the order of a vector or calculation once it gets set.  For example in the case of Channel Blend.  By default it takes four input channels and a four order vector to control them.  If you connect a two order vector to the input it switches to 2 channel blend which is correct.  But then if you try to connect a four order vector to it it doesn't switch back to a four way blend and there doesnt' seem to be a way to re-enable the four way.  This can be frustrating when setting up a shader if one accidentally connects the wrong vector to a connection thus switching it to a different order than intended and there is no way to switch it back again.