For me the OP now has a description of how a certain line up of cables performed in a system, that a proportion of the attendees at the demonstration were familiar with.
All Attendees had a familiarity with a particular Cable Brand, and the outcome of certain cables being a group wide unanimous agreement has a validity and is relevant to a Speaker Cable Discussion, especially when the request from the OP is referring to finding a way to reduce the cost on outlaying $17000 on cables.
I agree that there are going to be different viewpoints on how devices in the System and the preparations for the each cables audition may have had what one perceives as limiting factors on how a particular cable presents overall SQ.
The fact is certain very expensive cables sounded as limited in their SQ as the earlier used Cheaper Cables in the line up, and the owners of these expensive cables were aware of the close comparisons, and were not in disagreement.
I feel that on the day of the auditions, the descriptions offered by individuals were very closely explaining the perceived strengths and weaknesses of the cables, as I was in agreement with most of the terms being used.
On a side note ESL 57's were not the speaker in use on the day of the comparisons.
I am myself a owner of 57's, and like the the suggestion of investigating how to remove the attached electronics and make them function as standalone off board contained devices.
As for the stripping of the Grills and the Dust covers, and then putting the 57's or any Quad ESL into daily use,it might just be worth offering a description of what this could mean for oneself, or another person or pet, if they were to make contact with a unprotected Quad Fully Charged Stator.