If you use heavy set on kickoff returns it puts all of your backup lineman, 2 fb, and 2 te in for the kick return.
Remove your backup lineman from your lineup and it uses your starters. Run nasty streak or vanguard or whatever on your starters and let the cheese begin.
I was having a lot of trouble returning kicks and this has helped. Ive popped 3 to the house recently.
(Ive also noticed if you dont mash sprint like when you run the ball on offense it helps on kickoffs as well)