When you mouse over a heart, you get a tool tip that tells you the level of the heart. It might be nice to add a level or level range to the tool tip when you mouse over a scout to get an idea of the level(s) of heart(s) covered by that scout, in the event you are presented with multiple scouts progressing on a map and aren’t really sure which way to proceed.
I’m always reminded of this when I’m doing map completion (or a character on level) and I’m in Snowden Drifts. When you come in from Wayfarer, you are presented with quite a few scouts as you move in after the first heart, and it’s never clear whether you should go up or down first (assuming you are looking to do the zone in a level progressed order).