From the article:

For home users, unfortunately there isn't a simple solution for preventing this type of attack, until or unless Apple releases a macOS security update to mitigate the vulnerability. Cavallarin describes a possible temporary mitigation (opening /etc/auto_master in a text editor and adding # to the beginning of the line that starts with /net).

what are the implications of making this change to auto_master, beyond risk mitigation (i.e. to everyday use)?

Cavallarin explains it in a bit more detail on his blog[1]:

The first legit feature is automount (aka autofs) that allows a user to automatically mount a network share just by accessing a "special" path, in this case, any path beginning with "/net/". [..]

[1] https://www.fcvl.net/vulnerabilities/macosx-gatekeeper-bypas...

Assumably commenting out the line quoted by gp disables automount for network shares which start with "/net" in their path.

I am wondering this too. I see that `man auto_master` describes the purpose and format of the file, but I'm still trying to grok it.