I think we must know more about the microcode, pin out, dedicated programs, Api's, datasheet and etc. It will be more easily to improve the otimization and create mods.
For example, some crazy dudes want to make their V5500 to use 128MB, with the pinout help, they can make it.
Other example, SimGL is a api created by the Quantum and it is similar to the OpenGL. It runs just like the OpenGl ICD created by the 3dfx and it uses the Glide 2 and 3, but there are some diferences.
Well, I created this post because someday this cards will be... obsolete (it is hard to say this), but the knowledge must be preserved.
Well, a lot of info is in that archive (~40mb) with driver & bios source codes, that was leaked years ago.