Andrew:
I have a DS1, but look over here:
viewtopic.php?f=1&t=5853#p33536First photo is side view of boat on the trailer, she is supported by two bunks and two keel rollers, one at stern, one about a 2 feet forward of the centerboard slot. Remember, the DS1 has a single hull, no floor, but I believe the hull pressure points are about the same. My boat is also very early, it has wooden seats, not molded in. Note that I have a stringer (long beam, going fore-aft) 'glassed into the hull (on the topside, of course) right about where the seat-front goes on the later DS1's, DS2, and DS3.
For what it's worth, I've just flipped my boat over for hull refinishing. The P.O. hadn't taken the boat off it's trailer for about 20 years, so I was really eager/afraid to examine the bottom up close. Good news - the bunkers did not deform the hull at all. Flipped upside down, the hull shaped was still perfect. Bad news - a whole network of gelcoat cracks and even some chips radiating out from the bunkers. No surprise, I guess, but aggravating work to fill in. More significantly - and this is completely unscientific - I went over the entire hull pressing in with my hand and putting my weight on it to see where the hull flexed significantly.
Long story short, the spot that flexes the most is just forward of the stringers on my boat/the seat front on your DS2. Approximately next to the hinge of the centerboard. This is also right in front of the trailer bunk (at least in my boat), running for about 1.5 feet in from the front of the bunk, on the planing section of the hull - the flat part. That area is very soft, was full of gelcoat cracks on my boat and I could flex it 1.5-2 inches with a good push of my hand. Again, no surprise, I noticed that the same are flexes from the inside when I step on it. From inside, the weak area is from the line of the cuddy opening and forward about a foot or two. Looking at your on-the-trailer photo, it's about the same place, in front of the bunker and behind the mast.
My conclusion? I need better trailer support in that area. I have some nice 2x8's sitting in my lumber pile, I'm thinking of using them for new bunkers, about 2 feet longer going forward than my present bunkers. But I don't know if such a bunker would actually touch the hull (support it) all the way along it's length. I'll so some testing while the boat is still upside down. I may have to build up the front side of this proposed new bunker, otherwise I'll have to rig some sort of cradle. Keep an eye on my DS1 post (#37) and you'll see what i wind up doing - eventually.
Best,
Tom