Hello, i used that trailer also. What I did, and have seen others do, is take the two center cross members, the two at the folding point, and place them inside the frame rails. Basically doubling the frame channel, then weld/ bolt them in place.

. It strengthens the frame where it would have folded in its projected life. I have seen others add an extra cross member, cause the center " gap" is larger, some do not. I didn't, and so far, so good. Didn't show, but I put the axel on top of the springs to lower it some. This is what I did, there are more ideas different than mine, there is a lot of good knowledge/ experience on this forum. Coyote