Although I can't remember why, I do remember that a long time ago (15 years or so), there was a reason. I think it had to do with the fact that exchanges should flip the formation across the dividing axis like a mirror.

For example, from normal Facing Lines, do the following:

Lines Pass The Ocean Thru;
End Girl 1/2 Circulate;
Wave Based Triangles Exchange

I believe, that, in the old days, we didn't necessarily think that it ended on foot prints, hence the exchange from here ended such that the formation was flipped to the other side of the set.

Maybe the way to call the 'spots-to-spots' version is to say "Working to spots, Exchange The Inpoint Triangles"?

I've avoided calling these variations for so long, that I don't think I'd balk much if the caller expected the dancers to end in the same set of starting footprints.

In asymmetric sequences, I sometimes have a Diamond on one side and Box or a 3 By 1 Triangle on the other side. I call "Exchange The Diamond or Box (or 3 By 1 Triangle)". In such a case, I expect the formation to be flipped to the other side. I do not expect the dancers to do Circulates into the other formation ending on the original footprints.