I know soon after the trimming scandal was publicly revealed cardbuff stopped sending out daily emails (which was essentially endorsing many trimmed cards on ebay).
Mathis used to have a testimonial on PSA's web site endoring it, which I no longer see:
https://www.psacard.com/About/Testimonials/
The connections revealed on here by the original poster cannot be denied. Even from years ago when Chad Thyzell was selling the trimmed and sheet cut cards of Jason Koonce under superiorsports on ebay or some similar name.