I think they are saying that by adding the "2nd hose" you turn the cylinder into a DA cylinder and you have to adjust it manually with your non-float valve. You can't turn a non-float system into a float one by adding only a 2nd hose, but you can make the cylinder adjustable in a "non-float" way. That's my take on what they mean. They are saying that non-float, but adjustable via the 2nd hose is better than no adjustment at all.
Of course, if you want to add a 2nd hose and a valve that tees into the pressure side, you could open that valve and allow the cylinder to float while in use and then close the valve to operate the cylinder in the transport position.