#1 is an instacall IMO if Button is a thinking player. He puts you on nothing (nobody leads that strong with a set), he puts the PFR on something that can be pushed off, he puts CO (shortstacking donk) on a draw of some sort. He can be shoving with a range much wider than the 3 hands that beat you.

#2 is tougher I think because the button has to assume his shove will be called at least by the CO, so semibluffs make no sense. I think hard about folding this one.