You get Logan's first heart by staying with Logan. You don't get it if you encourage him to go to the bandit's camp and/or go after Bernard. Logan has se scenes, but only like three or two (for now) and at least two of these are one-time.
Regardless if you want his hearts or not, I suggest discouraging him because I know that options marked in red (Like encourage him, let the lizard's tribe succumb to the curse, etc) usually locks you out of others events because you need the "good ending version" of the characters to progress.