Well... it’s not supposed to be Art ... it’s a camper TRAILER eh ???
LT, the idea of an All Foam hatch has always been the theoretical Ideal

.. Simple ,Ultra light , retains its shape , keeps the rain out ...

I still firmly believe we can heat bend the foam (no kerf cuts needed) to achieve the contour for a really nice one piece hatch . How Cool would that be ...

You could even canvas hinge it , and that would contribute even more to the overall lightness of the trailer ... the lighter you make the camper , the more of Your stuff you can carry along ...
Having bent a Lot of 1/4” and 1/2” foam for model planes (see pic, looks like a camper with wings) , it’s so easy , and the foam once cooled stays in that shape forever, unless re-heated and bent another way ... Have to get the foam to 190F and bend over a form or jig of some type ...
