Mel, The back slope on the kitchen is just a
Trillium, "feature". The sag on the upper cabinets happens because
Trillium didn't put any supports between the counter and the upper cabinets. This problem is worse on the Trillium 4500. The kitchen is longer and still not supported.
But don't worry. Fibreglass is "plastic". That is, it will deform under stress and stay that way. All you need to do is stress it back up. I use two telescoping support bars in the winter to push the rear side of the kitchen and the roof vent back up. You can get these supports at Princess Auto. Currently they are on sale:
https://www.princessauto.com/en/45-t...t/PA0008822124
The reviews are not great on these, however they provide enough support to get the job done.
For more Trillium advise check out this post that I did recently:
https://www.fiberglassrv.com/forums/...tml#post856449
I see that you have a front dinette 1300 Deluxe. Nice!