It looks like you pretty much just grabbed ALL losses under Bronco and Lavell and called them a "signature loss". I was much more selective about Kalani's signature losses and only pointed out the losses to bad teams or embarrassing losses to good teams.
Bronco:
@Michigan 2015 (31-0) - Agreed
Utah State 2014 (35-20) - Agreed
@ UCF 2014 (31-24) - UCF was well-respected and playing at home
Nevada 2014 (42-35) - Agreed
Memphs 2014 (Bowl) (55-48) - Disagree that this was a signature loss. 2 teams evenly matched in a bowl game.
@Virginia 2013 (19-16) - Agreed
@Notre Dame 2013 (23-13) - No way.
@Boise State 2012 (7-6) - Nope.
Oregon St. 2012 (42-24) - Agreed
@ San Jose St. 2012 (20-14) - Was this the year SJSU finished in the top 20?
**0-3 vs. Utah
LaVell:
Florida State 2000 (29-3) Agree just because we only scored 3 points.
@Air Force 2000 (31-23) Nope.
Miss State 2000 (44-28) Nope.
@Syracuse 2000 (42-14) Agreed.
SDSU 2000 (16-15) Nope.
@ Colo St. 2000 (45-21) Agreed.
@Wyoming 1999 (31-17) Agreed.
Marshall 1999 (21-3) Agreed, though the team was decimated with injuries by that game.
@Fresno St. 1998 (31-21) Nope. Fresno was good.
Tulane 1998 (41-27) Agreed.
Washington 1997 (42-20) Meh.
@Rice 1997 (27-14) Agreed.
@UTEP 1997 (14-3) Agreed.
@New Mexico (38-28) Nope. UNM was very good that year.
**2-2 vs. Utah
"Signature losses" have always occurred with BYU - it's not something BYU only suffers under Kalani.