One easy trailer modification that can be explored is a cradle that tilts to between .30 and 40 degrees. I have seen a few cat sailors in Durban, using that modification.. Albeit with smaller boats.
It is very difficult to compare the ECO 5.5 with the ECO 6 which is learly shown in the info material you already have.
Genereal, ECO 6 is "Double" the boat of the ECO 5.5. So it has not only a lot more space in and outside but is also more seaworthy. On the other side it is not a lot more work. I have right now no time, but I will explain the big difference in stability of a 2,5m boat and a boat with a beam of 2,84m. By the way, at my download page is a program where you can calculate by yourself the difference. "Dynamic stability" program.?
I will not mention any design and designer who had problems with the instability of there boats for obviouse reasons. Before you change to a smaller boat. I would first talk to the traffic control autorities. In 90% of the counties in the USA you can have special permissions for wider boats.
