but that's not a ding on Rex, who I think is awesome. It's great that you found a source that puts Rex as the #2 TE in the country; there's also plenty who have Kuithe ahead.
As you note, they do different things; Kuithe has racked up more yards; Rex has been a bigger RZ threat.
I even stated that I think the BYU TE room has more upside. Rex is hard to judge because he got a ton of TDs, but a lot of those were also against North Alabama and Texas State while he had the #2 pick in the NFL draft throwing him passes. On a team that scores 5.6 TDs per game, there's a lot of touchdowns to go around.
So given all that, I'll defer to the longer track record and less unusual circumstances to put Kuithe ahead. Again, not an insult to Rex who I think is fantastic. I just think there's a good chance that 2020 ends up being his collegiate high in TDs scored (with a downgrade at QB, harder schedule, more use of Holker, and just having benefitted to some extent from random variance this year)