Watched BYU since the first Holiday Bowl, and I will disagree just a little
with your statement.
There have been other BYU QBs that had great accuracy on the deep throw (Wilson, McMahon).
My barometer is a little different since I've seen so many games. Does the QB consistently make good reads in the medium to deep range (10-15 and 15+), or do they stick to the shorter throws (<10). Zach has been outstanding in his medium/deep game. I loved seeing the deep crossing routes to Pau'u last game and really, all season long. Killer. So fun to see that part of the field consistently being used again, instead of only 1 or maybe 2 times a game in the past ... MANY years. Reminded me of the good ole days with Wilson where he was slingin it around almost at will connecting with crazy accuracy all over the field.