Yes!! The truss rod nut is very...VERY difficult to turn. My ggi6 bought used came to me with the relief set just right. Then I had a ggi5 and was really worried that so much torque was required to turn the truss rod nut. The ggi5 I have now came to me with the relief set so I have not had to adjust it. Both my bass necks have remained stable as expected.
As an aside, I also have a Modulus Q6 and it came to me with more relief than I prefer so I was amazed when the truss rod nut turned with very little effort and the neck relief adjusted with ease.
There is very little to complain about with Geoff's basses. I love them but there are two issues that I would like to see addressed. Something needs to be changed so the truss rod is more easily adjusted. Also, each of the Gould basses I have owned (4 so far) have had a nut that needed attention. One of my ggi5's needed the strings lowered at the nut and all of my Gould basses had nuts that had excess nut material on the top of the nut as though the string slots had been cut and then the excess nut material had not been removed. This is strictly cosmetic but it bugs me that these wonderful basses have a detail that needs attention.
One other thing I might mention is that before I adjust the truss rod I loosen the strings, stand the bass up on the floor, put my left foot behind the bass body with my left leg against the bass body near the neck joint and I put pressure on the neck to pull it into less relief while I tighten the truss rod nut. It sounds complicated but it really pretty easy to do.
If you are unsure about what you are doing with that truss rod adjustment, it might be much cheaper in the long run to seek professional assistance. It would be cheaper to pay for some shipping back to Geoff rather than shipping and a repair for a broken truss rod.