Indeed wire is a squirrelly stew. Considerable knowledge exists, much of it in the realm of very high tech-space research-at the fringe of measurement. High end audio "found" wire as a new frontier in the 1970s and some very good work has been done since. There also seems to be considerable borrowing of second-hand knowledge, repackaged with huge mark-ups attached - commonly called snake oil. But most oil has no snake in it and much wire technology is indeed real and crucial for ultimate performance. To the material dynamics of bare wire, add reactance of coatings and influence of geometry, and you see that complexity increases exponentially. We know much less than we don't know.
Exploration of these frontiers adds to the richness of our journey.
Presently I am comparing coil configurations as fed from the circumference or the core. The oscillation of the electromagnetic fields behaves differently in each layout. Opposing opinions exist among intelligent and qualified observers. Most say "it doesn't matter", which I interpret as "I don't wanna go there." Who knows where this road goes?