It's basically a bunk trialer but with rollers instead of carpet! Having lived with a bunk trailer under the last boat I'd be slightly wary without a couple of launch / revovery trials......
Agreed those "creases" do look a little extreme, but as that corner will likely be in tension due to the weight of the boat on the bunks acting on the pivots at the side rails it's the underside of that beam that will be taking the strain, and the axle should hold the side rails apart.
What I'd be more concerned about if you got a 115 Opti on your transom is the Gross weight. I can (just) tow mine unbraked legally if I put one of my fuel tanks in the car....... The ad says GROSS weight 750Kg (the legal unbraked max) - and you're realistically looking at about 200-250Kg of trailer there and a max boat weight in the region of half a ton....
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