I didn't really like any of the existing Leviathan Wilds inserts, so I built my own. It fits the Founder's Edition with fully sleeved cards and the Deepvale expansion with no lid lift and room left over for one more Deepvale-sized expansion if/when one comes out. I do not have the deluxe components upgrade and so I'm not sure if that would fit or not (it might require some tweaking of the token trays to work).

Getting both spiral bound books to lay flat was a bit of a puzzle, but I figured out that if you sandwich the player boards between them and put the spirals on opposite sides, it works perfectly.

I color coded the card trays (purple for leviathan decks, teal for character and class decks, orange for the damage deck, and green for the mutation deck), but that's obviously optional.