612 to 620 with 416-8A = Deeper bass?

Something I became aware from Voltsecond, is that very low frequencies through a tube amp increases distortion. If you are going to use a sub, you can limit the low frequencies going through the amp and decrease distortion.
Does anyone have experience with this?

I would think that removing damping would cause the box to resonate more? That’s why I don’t use boxes.
Yes I am super happy with the lows now. I won't push it any further and instead reinforce the bass with a sub. I need to play with the dampening a little more. Getting improved sound now after removing some of it. Next I will take it all out and work back from there.