My experience from 1996 is quite the oppiosite. I bought a S3 964 based card after those were on the market for more than a year, and I had to find that XF86 was running in false-color so to say. S3 sent me the printed programming for free by international airmail essentially no questions asked.
It turned out that the problem was the way the external IBM RAMDAC was wired to the S3 chip - easily fixed with a 2 or so lines patch, Back in those days manufacturers of graphics cards dodn't just implement a reference design, but had lots of choices which components to connect in which way, which didn't really make things easier for open source developers without access to every hardware variant out there.That essentially ended with the S3 Trio/Virge and the ATI and NVida 3d cards.
Thus spake the master programmer: "After three days without programming, life becomes meaningless." -- Geoffrey James, "The Tao of Programming"