That's great! Lots of space saved on the table!
One more thing I think this needs is something that covers the level sleeve to be able to track health. This cover would have sort of very narrow "shelves" so that we could lay the damage token in a line vertically (or rather at whatever angle the level card is) and a number near the center image to identify which monster took the damage. Because with this we can't track enemy damage, so something should be there to fix that. Ideally, that cover is detachable from the base so that it can be stored more easily.
Think that could be feasible?