Hm, the Edge Antialiasing is the only one that a Voodoo3 could do, but this is IMHO not supported by all Driver Versions.

I think the MikePedo 1.1 Driver made use of it, but it is limited to Direct3D.

Personally, I never saw a Voodoo3 do it, but I know it worked surprisingly well on a Voodoo2.

There might be more limitations, though, which I am not aware of (e.g. not all Applications might be able to use it)

Some Driver modders likely saw this nifty tweak and simply integrated it, without checking it over careful enough