Chu Gai wrote:

I am trying to allow the energy that would be absorbed by MDF to be
better utilized re-creating acoustical energy in the room.

It seems like you are missing the fact that relatively efficient home
speakers are about 1% efficient. IOW, if you want to worry about the
inefficiency of your speakers, you would do well to look elsewhere than the
sound absorbed by the damping of the wood in the boxes.