The best way to use the 0.8 is to boost immediately after pressing the jump button. The 0.8 tries to keep you at a constant velocity, but if you wait till the top of a jump (when your y-velocity is 0), you'll waste a lot of boosts accelerating.Just make sure Quote jumps to his full potential before using the booster.
I'm glad you know so much more about cave story than everybody else who's posted before you.ChimeApple said:It isn't possible, the Booster V.0.8 isn't capable to plunge itself onto the first block that's required to get back in the first cave... without the Machine Gun.