If we go back to the original question CAT.
As we can see Boeing has a reference CAT for each aircraft, and the State uses this.
In the example for the 737-800, you CAN, at 50T, flaps 30, have a Vref of 129kts...this does not mean you can use a CAT C approach.
The actual aircraft, depending on configuration, will have its own certified MLW.
For approach procedure design, the segment speeds will have winds added...
Some regulators require ground speed for the procedure designs as well...
The 737-800 is a CAT D. Some airlines, will play with the weights and configuration, to get the aircraft to certified by the Boeing/State to CAT C for access, or to limit loading to save landing fees, etc.