The esw9 is like a sweeter laid back version of the es700.
The esw10 has better and larger sound than both esw9 & es700, approaching an es10 in size but with more neutral solid wood mids.
The es700 is like a baby es10 in signature.
The es10 is a more "vanilla" and exciting version over the duller ws99, but ws99 just as large sound.
The esw11 to me is the best.
It is the largest, smoothest, supple & detailed sound.
Most woody sounding as well so has most tamed trebles which can be fixed with mod or pad swap.
The "Germaina" mod on the esw9 is good only for creating a more expansive and woody sound.
It is a fantasy to think it could sound like an esw10 because the voice coil is "tuned" to have a laid back sound with sweet trebles.
Trying to alter sound will suck life out of the mids. I know because I have tried.
I would recommend no dynamat but instead foam for sound dispersion.
You can try dynamat as well around edge of plastic housing for solidity but not on wood as that wood gives life to mids..
In any case, whatever you decide to do,
Do only one side at a time and compare to original side to see if you have a sound you prefer.