I don't know if the old Thread on this will be accessible, so until then I'm going to input what I've found, and what I've discovered.
First things first, here's the Link to the JBL "Technical Notes Volume 1 Number 12B" that talks about this. Unfortunately this is undated but is seemingly circa mid-to-late 1980's.
Note that NO LE-series nor AlNiCo magnet assembly drivers are discussed.
My testing compilation will be posted. I will also copy/paste here some experienced responses from the most recent exchanges.