Yeah it seems like a hard one to balance out; There was this one section with the feather below a floating platform, and that was the only time my bar almost ran out- perhaps more sections like that would make it easier for players to experience the effect? And you can keep it filled up if you remember to take the right path too.
Ah yes I did figure that strat out! but due to my shoddy execution, sometimes still ended up taking me down at times.
Another aspect of the game I liked but forgot to mention earlier, was how flying upwards without holding left/right makes you gain more height. Makes you have to think more about which option you're going for.