Yes, because the Free T measurement is not accurate, even the calculated versus Equilibrium Dialysis or Ultrafiltration can be off by as much as 40%. Neither method is perfect.
The Total T is a more reliable test.
Also the endocrine society recommends the calculated Free T, which is what my doctor uses to determine my Free T, that is until something better comes along.
He said a lot of doctors only look at the Total T, either due to a high degree of testing accuracy and or lack of knowledge.