A quick update / demo. I spent some time working on the emulation of an Asante FriendlyNet PC Card, this card was easiest to work with for me as it is well supported on the Mac and has PC drivers and uses the same DP8390 networking chip as the NE2000.
A custom driver for Mac to expose more features is not out of the question, but for now the support is limited to networking. I hope to have some discussions at the upcoming VCFMW about software/driver development on MacOS.