I've never thought of this before and I can understand where OP is coming from. I suppose it makes perfect sense to chose the most +EV situation, whether it be a long term result or a short term one.

My concerns are: the rocks at the table are making +EV moves vs you at the table as they take into consideration the change in table dynamics; and, this OP idea assumes that the new laggy fish is around long enough.

I say take the fish's chips while it's still alive.