MST via Samsung Pay is the same thing as swiping the card.

​​​​​It's easy enough to look up the physical credit card contact NFC limits, by country. Canada and Australia are quite high @ $100. The rest run roughly in the $20 - $30 (USD) range; if one tries to tap the card over those amounts, it has been reported that generally the machine will force an EMV chip insertion instead.

These days, especially in Europe, terminals are configured to allow tapping over those limits with The Pays; fingerprint effectively replacing signature or PIN. I could see situations where the shopkeeper might try to discourage, if not actually impede, folks from trying to charge over the limit without insertion.