A quick update with some info.
I’ve been riding the TT bike for a while, but after about 10 rides—or 1,000 km—my stem started making a really loud creaking noise.
It had been properly installed with carbon paste and tightened to the specified 8 Nm / 10 Nm.
After I sent Chris an email, a new stem was sent out immediately, and he confirmed that they had made the fit for the fork steerer tighter.
Upon measuring the old and new stems, I found a difference of 0.7 mm, Problem Solved 👌🏻 So, once again, excellent service from Velobuild and Chris.