I’m a self professed tinkerer as you know.
I can appreciate the technical mechanisms where #6 and #8 can sound subjectively different - but I’m not convinced this will always be technically better.
I wasn’t always like this. But enough discussions with John Swenson (Master Level Tinkerer himself), Rob Watts and Ted Smith has led me to understand some of the mechanisms at play.
The only way to know if a linear PSU is better than an SMPS is to see measurements of the specific ones.
An SMPS CAN actually perform better (lower ripple AND lower AC leakage currents) than a linear PSU - a vice versa.
Or you can go with gut feel and trust the designer. For example, John Swenson has shared enough technical information about these potential mechanisms that I trust his JS-2 and ultraCap LPS-1.2 are very very good linear PSU options. I also trust the SMPS’s of Rob Watts DACs (even Dave) for the same reasons, when he says they measure as well as his lab linear PSU.
For #8, again John S has discussed at length the potential technical mechanisms where different methods of shielding digital and power cables (which a lot of the expensive audiophile cables tend to vary in) can sound different - but different may not be technically better in some cases…
So I’ve been convinced by these experts that we shouldn’t generalise that all linear PSU’s are better than SMPS’s.
And I’ve been convinced by these experts that not all expensive digital and power cables are automatically actually technically better…
Edit: Andrew Mason (Analogue and Power Engineer at THX) has also shared with me , the same beliefs that SMPS’s CAN be designed to perform as well as the best performing linear PSU’s and better than some not-so-good performing linear PSU’s. There is no straight rule.