Hero UTG raise 3 BB,
Button calls,
SB shoves 40 BB all in.

Now its to you. You have about 150 BB and Button has 100 BB.
Do you shove here or call?

We are calling and always calling something like 88+ AQs AK. The reason we only call is that the pot odds offered to the button are alredy horrible enough that he can't continue with most of his range, going bigger doesn't change much.

If we call everything we put hands that snap call a shove like QQ-JJ in a tougher spot, now he can either call and we get an additional very profitable bluffing opportunity on any non Q-Jhi board, or he shoves, and we can fold some of our dominated pairs (he can't bluff shove efficiently because of the sb so my guess is we can fold a lot of pairs). Since the former seems better to him, we just give us an additional street to bluff if we just call, and QQ-JJ don't improve on most flops so it's good.

The worst we could do is shoving hands like AA-QQ and calling TT-88, that would be really really bad