However, Shaun Coon found that disabling the extension prevented him from making AppleTalk active on his Power Mac. Similarly, Don Foy could not access his Ethernet network with the extension disabled (running Mac OS 7.6 on his PCI-based Power Mac). This is utlimately due to the fact, as discussed here before, that the non-PPC version of SLM is needed to access the 68K-based library files that, in turn, are needed to run 68K software in emulation mode on a Power Mac.
Update: Mario Crosina reminds me that almost this exact issue was previously covered in an Apple Tech Info Library file. In fact, I had mentioned it myself previously on the Late-Breakers page! (<sigh> It's gotten to the point where I can't even recall my own writing.)