Since I’m in Free-mo, I have a lot of experience with “layouts” that have to be carried, frequently through doors.
Your best design will be a balance of strength and lightness. There are various ways to get there. Since you won’t be moving this a lot, probably going more towards strength will be a good choice. I recommend a maximum weight of 50 pounds. The design weight might also be affected by how many helpers you have.
And I recommend considering where you will place your hands when you pick it up–maybe handholes or handholds?
I would keep the “support system” separate from the layout, saving weight. Thus, legs would be removable for transport. Or you might want a table you could set the layout on.
During the move of the layout, you may want to arrange protections for the top face of the layout. This could be anywhere from a full cover that is attached to the layout after you’ve loaded it for transport, to just being super careful.
As an example of weight, if you made the basic layout with a 1/4" plywood top, 6" sides of 1/2" ply, and four internal crosspieces, 4" high, of 1/4" ply, it would all weigh 25 pounds.
The waffle design is an interesting alternative. In my experience, it is not especially weight saving, however. It might gain in strength, though.
It’s not too hard to figure out weights of the basic frame before you build:
1/4" ply weighs .0048 lb per sq in. 1/2" is .088 lb. and 3/4" is .0132.
Just figure the areas of all the plywood pieces and do some addition and multiplication. Not necessarily in that order.
Ed