Max Tow Option, $395

I am wondering what the "Max Tow" option for $395 really adds (screenshot below)?
The description from Ford is not very conclusive, and I haven't found a clear answer either using the search function of the forum.

Does it increase the GVWR/payload and/or towing capacity rating, especially for the powerboost?
Any other reason to pay or not pay for it?

Thanks much!