I purchased an 04 Lance 1121 in July of that year. Was advised that I didn't need to support the floor while occupying the camper when off-loaded. So, I haven't for almost 9 years and mine has had a tremendous amount of use in extended travel and full timing.
In retrospect, I can only recall a handful of campsites that wouldn't require at least a modicum of excavation to insure a level X-box. In fact, I'm sitting in an adult "Resort" park (lol) today and every unit is high; front/back/on one side or the other. I've got the smallest footprint in here and my Atwoods are at different levels.
Personally, I couldn't justify hauling the extra weight of the plywood
X-braces. That's a lot of adult beverage and watermelon. We're truck campers... go anywhere, anytime, SUV folks. I believe your Lance is up to the task.:W