I now know why you said it’s going to be system dependent.If you'd want to describe why you prefer ALT1 and which power supply you use it would be very useful data for us
Originally I used a dark sounding rj45 cable and preferred default default.
Then I swapped to a brighter sounding one and felt default default had lost the rich depth so I might as well do default alt1 (the latter being the switch) because when I tried it at least it gave me more detail.
Finally now I switched to a more neutral one and while default default was good, I felt alt1 default (this time alt1 being on the router) had both depth and edge acuity which I like. But I haven’t tried alt1 on the switch in this combi.
For those who intend to do this experiment, do note that your choice of cables probably matter a lot. I expect most people will probably just use a DAC cable though which has less options so maybe this won’t be an issue.