IMO, it's not really X's and O's stuff, just coaching points. On straight up fakes where he throws to the gunner, have the CB play up on the line of scrimmage and jam their guy at the line. Make sure he's aware (and I am sure this is the point in ST meetings this week) that he has pass coverage responsibility first. Where Hekker has beaten guys is when they are playing like a soft zone. IIRC, the Pats will sometimes put two guys out there on the gunner. They will be fine.
The other thing we've seen Hekker do is throw out of punt formation with the gunner faking a jet sweep. The coaching point here is to make sure the outside LB on the side where they faked from knows he has pass coverage on the TE. Basic defensive rules IMO. Leave the CB in man, jam coverage, and make sure you cover the gunner like a cheap effn suit.
This is one area I am 100% confident in that BB won't get caught on. I think he will protect against the fake first and set up the return second. He will have confidence in Tom and Josh and the offensive scheme to be able to win the field position battle and not worry about setting up a return. I will go one step further that if the Rams are bold here, BB will make them pay. If Hekker has the green light and get's cute, they are very vulnerable for a pick 6 on these type of plays. Play defense first, know your responsibility, and do you job. No way they get outcoached here.
Here's the video of Hekker's fakes. I looked for Pats punt return formation but couldn't find it. I am sure one of the other guys can find it, however. You'll see what I am talking about