The force needed to start the 5er moving or to stop it is the same regardless of the hitch. Having a gooseneck adapter does not magically increase the force required to move, stop, or turn the 5er. The force applied at the pin does not change.
I will not get into an argument about this but consider that your 5er is like a flag on a pole. The flag does not have more or less stress based on how long the pole it. The pole may have more or less stress based on length but the flag (pin of the 5er) does not.
