Thanks for relaying that information, Brooko.
It looks like HSA is associated (under the same financial umbrella) with one or both of the companies that I mentioned. That's great that they're paying attention to QC.
One thing to add: Molex does produce its own drivers as well, most notably for Final Audio, though I've heard that they're closely associated with Sony. I still don't know the relationship between the two. Star-Micronic used to produce for Etymotic (for the ER6/6i) but seems to have gotten out of the game. There are also a couple other companies, though I don't know if they make BAs oriented toward audio or not --- perhaps they just produce for hearing aids and other microelectronics. I did not know about Cresyn.
I can't tell what they're using to measure that graph, but hopefully it's not via an IEC60318-4 coupler, or else it'd have severe high frequency roll-off. It it's 2cc or some other straight-tube coupler, then it'd be less of an issue, though there'll still be quite a bit of roll-off.