If tokens are dragged onto map from PC combat tracker entries, the targeting arrows for that token should always be visible on the client owning that Matching PC.
Also, targeting arrows are shown for "selected" tokens (dark circle) and when hovering mouse over tokens.
As Bidmaron mentioned, the challenge was that targeting was user to token, so GM targeting wasn't visible and multiple characters not supported. Arrows allow display of token to token targeting. Initially, all targeting information was shown all the time, which was to much display confusion, and was toned back in v3.0.2.
Regards,
JPG