From Pomeroy (who excludes D-2 opponents), D-1 average is 9.8% of missed shots blocked; BYU blocks 5.8%, with 12.6% of their own shots blocked.
Cougars had similar weakness on the defensive side last year of not blocking shots, but on offense BYU was somewhat better than average in avoiding blocks.
This is only data from three games and as Neilson and Kaufusi get more minutes, defensive blocks should improve. Austin has never averaged one block per game and Mika was not inclined to do blocks either. Also SDSU had 9 blocks and are top 10 in the nation in that defensive stat.
Since Hartsock, BYU has been below average on the defensive end in this category.