Yes, I have - and I probably over-engineered the installation, but I'm happy.
I actually replaced my bow and stern cleats as well - it was an over-winter project, and frankly I believe that strong cleats are cheap insurance. I went with 8" stainless-steel "yacht cleats" from BosunSupplies.com - and for the bow and stern cleats, I took their recommendation and used 3/4" marine plywood backing plates between the under-deck and the fender washers. (The midship cleats were an exception; there wasn't room for a 3/4" backing. BosunSupplies recommends wood because it has some "give".)
If your Mac was built after (I think it's) May 1999, the deck was braced with a sort of "corrugated" lay-up of fiberglass cored with open-cell foam. This is much less worry than a balsa core, because you don't have to drill-and-fill to protect the balsa.
I put my port cleat just inside the molded "toe rail" and a bit forward of the hand-rail socket ... used a zip-saw to cut a hole in the headliner, peeled that off, and drilled for my cleats. I put a short "riser" of StarBoard under the feet of the cleat ... I used 8-inch 'yacht cleats' from BosunSupplies.com, and they weren't quite as high as I wanted to clear that "toe rail". (I pre-drilled the risers and stuck them down with 5200, then bolted down the cleats to hold this in place.)
Below the deck, I used a 1/4" piece of StarBoard and a whale of a lot of 5200 to "even out" the chopped-out corrugations ... and the largest fender washers I could find, for right under the lock-nuts.
Next day, I bedded the cleats with LifeCalk and pulled them down "just a little" till the caulk was cured - then I cranked 'em down tight. I covered the holes with varnished plywood plates, routed out underneath to make room for the bolts.
I also added some "rub strakes" of 3/4" stainless steel rub-rail, glued down with 5200, to protect the lines and the "toerail".
A few weeks later, I made a mistake trailering-home from a day on the water. I left a 3/8" nylon dock line tied to the heavy steel railing beside the ramp - and broke the line ...

(Notice the blue marks on the fiberglass to the left of the cleat.)
"Priceless!" :dance: