Question re. Load Impedance

Rest In Peace
Joined 2023
A client is auditioning a phono preamp with a Dynavector XX2 L. While setting it up we determined that the 125 ohm setting was good, after I left the client tried different load settings including 10K, which he liked. This is a bit counterintuitive, as I would have expected this to be extremely bright. Is there a technical reason why this would work?
 
proper adjusting technique is a must, TT itself can't be adjusted with pure luck

then - next link in chain , calculus for loading impedance and ( if applicable/needed) capacitances are necessary, but only taken as starting point

then ear must decide what alteration is better than starting value
 
Well the reason is that I am trying to understand what on the surface seems contradictory. Forgetting the client's preference for the moment I don't understand why a vendor would have a 10K setting, I assume there must be a reason.
 
Timely thread. I just got a Mani 2 phono stage so I could boost the output to my pre. Having to crank the volume up much higher for a particular source has always bugged me. The Mani 2 has adjustable gain and loading. I changed the gain from 42 dB. to 48 but at an apparent slight loss in SQ. The unit comes with the loading set at 47pF but can be raised or lowered. Will changing the loading affect the gain?