Long Floats

The reference material sent on Closed Loop fibres revealed a detail which may be of note regarding the fibrous aspects of the case. See mention of a special fabric as follows...

Cinchilla: A cotton, wool, and even synthetic fabric of sateen or twill construction with extra fillings for long floats.

This is a fabric which can be made from natural and synthesised sources and bears a cutely disguising name. Note the talk of 'long floats'. Combining this with the name of the fibre suggests to me a Flotilla, something highly pertinent to this case. Perhaps the Michigan crew were looking at shipping/manufacturing such a fibre for use in their various operations. Perhaps your novel simultaneous spinning experiments are something akin to this manufacturing process, though may need some kind of modification or change of variables to get the desired results.

Are you aware that certain models of turntable favoured by audiophiles and disc jockeys have a pitch adjustment facility which allows, by means of a slider, many (14) speeds of rotation. It enables music to be played between the notes of conventional key structure, similar to the effect of de-tuning an instrument, but on a song-wide scale. I hypothesize that perhaps an unorthodox rotational speed could create some kind of resonance between the two spin sources, allowing for a qualitative change in results. This could operate as some kind of vibrational/resonant cipher - find the right combination of rotational speeds in the two sources and information may be gleaned from the beat notes of the resulting cross-rhythm like some kind of low frequency morse code.

With regard to working out some kind of timeline of 'disappearances', Perhaps Costa's mid-90's 'disappearance' was her dropping out of the state education system to form a band (possibly an early guise of Broken Social Scene), with the interim years spent touring the low-level festival circuit until the band's profile was raised enough to force her to return to the overground. As previously noted, the festival circuit can be a great way to fall of the radar should one wish to do so. Though, as a known Obfuscationist, she could easily disappear and yet be active at the same time, most likely under a pseudonym. Happy said the mixtape couple stopped visiting circa 2005. He doesn't recall when they first began appearing on campus, but says he became aware of them a couple of years into his studies, around summer 1995. I do not know how this fits with your theories.