depends on the UTG limper for whether to be the initial raiser.

Is he limping a lot UTG, does he hang on for too long post flop, is he easy to play against? If he has been limping a lot and playing fit or fold then it is an easy raise. Unless he is only limping med+ PPs from UTG (and that almost never happens) then I would default raise this.

This way if the 20BB SB wants to reraise, you can call and take the (hopefully) flip as long as you have succeeded in folding all of the players between you without any worries.