@Ryan:
We are using garden variety FT232R chips (VID 0403, PID
6001). (Well, almost garden variety -- we've reprogramed
their EEPROM so you can wiggle CBUS 03 in bitbang mode which
turns on and off the 5V power to the connected instrument.
That's why I need libftdi in the first place...)
Your udev solution sounds elegant. There's just one
problem: Window's isn't Linux. :)
I'll keep digging.