For people like me who are wondering what is the difference between the 2 forks:
According to Gemini they are effectively the same, but 3of0 adds an extra step via a setting. Both seem to adapt the biter AI to match the vanilla changes from 2.0 to 2.1.
Gemini prefers slightlygrilled's version because it is apparently a more elegant solution (code-wise). Although it probably doesn't matter as long as you don't encounter a crash or bug ^^
Also if / when the original mod is updated, please post it here so that I'll get a notification :)