the limit on i-o video memory is probably fixed in the bios code that runs the trident chip.
i have a MSI mobo with a later version of the trident chip and i can set the video memory in cmos, just like the i-o, but it stays set.
my MSI via chipset uses the same via 4-in-1 and trident drivers as the i-o.
while some people have rewritten parts of the bios to boot from hd and to fix the usb bug, no one has gone after the video ram limit.
since each display controller is different, a fix for one make of chip most likely will not work with a different make.
someone who can write good x586 code should look at different installations and bios for the same or similar chips by the same mfg. in this situation, different uses of the trident cyberblade and its via twin.
if you read the data sheet on the cyberblade, you will see the chip can input and output composite television video, but no body has played with that possibility either.