He only played 9 games as a sophomore. And he played them on an excruciatingly painful high ankle sprain that he suffered early in the season against Ball State. He was supposed to be out 4-6 weeks, but made it back in 2. He also broke his collarbone in camp this year when Alohi Gilman landed on him and a drill. Kmet made it back by the UGA game and starred in his first appearance of his junior season.
He's an extraordinarily fast healer. He plays through pain. He runs through arm tackles/contact.
As a junior, Kmet tied the all-time record for TDs by a TE at ND (which is Tight End U - Fasano, Eifert, Rudolph, Niklas, Mack, and now Kmet, just in recent years). I imagine his production next year would've been record setting with his QB and all 5 OL returning.
At the end of the day, I don't think the Colts will even sniff having a shot at him. Kmet may go in the first round (perhaps to NE).
He's the clear #1 TE in the draft at this point, and the only "weakness" in his game is that he could still develop/get stronger as an inline blocker.