Well, I did a little more research and reading, and discovered:
The Trident 9440 is supposed to be fully supported in the 3.2 SVGA server
16bpp can be had by adding:
Option "linear"
to the Device section for non-PCI cards - by default linear mapping is turned
off in the server for non-PCI TGUI cards.
24 bpp and 32 bpp still do not work - the server claims they're not supported
for the tgui9000cxi chipset.
Just passing along what I've discovered.