Woh, you must be super dexterous haha! Glad that it worked for you though.
The charge does not deplete with fire but it takes quite a lot to charge. This was by design to make it more challenging. The orb does stop growing at a point so that it does not get too big. However this does highlight that i need some extra feedback to tell the player it is still charging. You should still see your fire rate increase but perhaps I should add something more obvious or reduce the amount of charge required.
Thanks for this feedback, it is very useful.