Thank you for the detailed feedback!
I'll consider adding the early dismount from Glider and Rocket. Sounds like a good idea!
Downward boost can only be used when flying above Calli's height and a bit below the far view ceiling (around the clouds), so if you're moving too fast vertically you will fly past the window really quickly. It's better to save it for when you're moving more horizontally than vertically.
About the charging, it happens while flying at a certain height window, which is slightly narrower than the activation window. You will get a lot of charge when using glider or rocket since you're kept inside the charge window for a relatively long time. You will get almost no charge when zooming vertically.
Once again, thank you for the feedback, I really appreciate it! :D