John,
I used to use an EZloader trailer just like your and Denny's. The way Denny has his set up is right.
When I got mine it was set up so that the outer-most rollers were were on the middle planing surface, and the inner rollers on the inner planing surface. The boat never sat level on the trailer. Oh, sometimes I would get it nearly level, but not quite. As we don't see roller-type trailers that much in Florida, I wasn't sure what to do.
A friend of mine who has a Seafari (a former co-worker of Denny's, too, btw), told me to move the hull supports outward until the outer rollers were just outboard enough to sit on the outboard planing surface. Using a shop hoist, I picked up and blocked the boat about 2 inches higher than it normally sat on the trailer, and then crawled under it and moved the hull support arms outward on the crossmembers until the outboard roller sat about 2" outside of the hard chine on the outboard planing surface. The boat also sat lower on the trailer than before by a couple of inches when I was done.
After that, the boat loaded straight and level every time.
When that trailer needed replacing, I got a drive-on type.
__________________
Common Sense is learning from your mistakes. Wisdom is learning from the other guy's mistakes.
Fr. Frank says:
Jesus liked fishing, too. He even walked on water to get to the boat!
Currently without a SeaCraft 
(2) Pompano 12' fishing kayaks
'73 Cobia 18' prototype "Casting Skiff", 70hp Mercury