As far as I’m aware he/they are the holders of the access door STC.
I’ve had no personal experience so can’t say anything about how things are run currently, but I guess I’ll be direct: keep eyes open and tread with caution.
https://www.tennessean.com/story/new...-case/7136775/
However they do have some potentially useful STC’s (and one to best avoid)…
In their defense, I was interested in one of their STC’s and they discouraged me from it as really not necessary in my case.
Caveat emptor