Re: Optimum room dimensions.
My research shows that the optimum ratio of room dimensions depends on the size (volume) and shape of a given room. So there is simply NOT one ratio that is always optimum.
My conclusions come from studying Oscar Bonello's work from 3 decades ago. Briefly, he showed how the frequency and strength, distribution and statistics of room frequency modes form a basis for catagorizing room dimension ratios.
My article on this subject appeared around 1999 in Speaker Builder magazine (I'm not at home to specify exact date).
As a live acoustic music and accuracy git myself, I would not argue with your priorities.
However, in my opinion you've confused the behaviour of some of the groups. There are in my opinion several major groups of purchasers - e.g.:
i) Those who are deaf to the blandishment of snake-oil salesmen, who trust only their own ears, and are wise enough to use a wide range of listening material when selecting systems.
ii) Those who belong to the first group, but also believe accuracy helps make things sound better, and that measurements are a means to this end.
iii) Those who think only the ears count, but happily use highly-distorted starting material to make their judgements.
iv) Those who think they only accept the evidence of their ears but are influenced by snake-oil salesmen; and
v) Those who will accept any received "wisdom" without making personal checks.
I have no argument with members of the first two groups - albeit the effects of sound level, and human suggestibility (or overcompensation for the latter) mean that it is extremely difficult to be a member of the second (unless you have loads of friends with appropriate systems who will loan them for a week at a time).
The "distorted material" group is likely to be disappointed when they get the system home; and the other groups will generally overspend on snake oil.
Accuracy measurements do not support high-cost cabling. Both measurements and blind listening tests suggest that only resistance and inductance are important. I probably go further than most, as I use standard "twin and earth" mains cable for speaker connections. Conductor area and number of paralleled cables depend on distance.
While all of you possible sound engineers hark away at ear canal resonance, amp slew rate, mathematical dimensions of listening room and such esoteric funda, for the average listener who is a million mile away from such facts, what he likes when he hears is what matters. How in the world would one know how a royal philharmonic would sound when buying a CD. All that matters for one is how he likes when it plays on the device. So I would rather side with Audiofools saying accuracy matters but not at the expense of good sound which is the subjective part. Ironically people are willing to trade the latter for the former, go figure.
Knowledge of EM in general and hysteresis in particlar is also how I separate out the men from the boys (& other pretenders) in the EE profession…