I don't see any major problem here.
The boat might need to be pulled another two inches forward and the bunks need a few more bolts to attach them to the supports, but the design overall looks normal.
It is a bunk trailer without a doubt.
The rollers are only there to catch the "Oops" and there would be a lot more of them. Not just 2 or 3.
If they were meant to support the keel, they would be on top of the cross-members and would be adjustable.
Roller trailers sometimes have two small bunks just to keep the boat from tipping.
This trailer has 4 full size 6" bunks, flat side up. Real Bunks!
Looks good to me!