Got the driver working for the onboard LAN on the Biostar TF7025-M2. Chipset is MCP67, and I had to manually add the deviceid (054c10de, for those keeping score at home) to the info.plist of forcedeth-nockd.kext. Was pretty crashy at first, but after disabling IPv6 it seems relatively stable. Will report back if I get more crashes. Thanks very much to planetbeing and everyone else who's worked on this!