I was watching this video about a pretty remarkably skilled boxer and saw some principles of kata application:
Mostly it was the angles. Lomachenko moves around his opponent to find angles where he has an advantage and the opponent is overwhelmed by strikes. Many of the kata angles seem to have a similar function, given Mabuni's advice on kata angles.
I also noticed the part where Lomachenko is working around the opponent's arm, reminding me of one of Iain's applications of Heian Shodan's opening sequence. He didn't control the limbs, but he did work around the obstruction.
I also noticed the limb control at about 1:05 of this video:
I realize the "chi master" guy is fighting with nonsense. But the opponent - the guy with real physical violence to bring - has him completely controlled by the arm.
When you look for kata bunkai applications, you can find them lots of places!