I’m surprised that you cannot buy a bass cab riser ( think nicer beer crate ) as it would be popular in getting cabs raised so you can hear better
A nice black tolex unit with rubber feet say 12” tall would make all the difference.
Anyone fancy making me one !! For a good price of course !!
Double wall cardboard cut so all the top edge forms a plane that supports the bass of the cab while the tail of the cab sits on the floor. Solid as a rock but don't flood it with a jug of beer unless wrapped in duct tape. It will stow in the cab port.
Z plate hooked over cab to hold amp or the tall feet trick. If you spec it right it will also stow in the cab port.