Like the OP on the link you posted, I have Character Config > Control Settings > Filters set so that "While weapon is drawn" I target enemies only.

But, I'm still targeting pets, NPCs, and almost anything else constantly while in combat stance/weapon unsheathed. It seems to be a bigger issue in groups or where their is a lot in the same area (eg Fates)
I'm using Xbox 360 wired controller on PC, and selecting with A, then scroll targeting with the directional pad.

It is extremely frustrating as I am an archer, and makes it impossible to do Fates. And hard to do instances.