button push frequency came down to balancing game mechanics.
The reason to push it, was that it blew up all the projectiles flying towards you (which ramp up in frequency, which gets reset when you push).
Reason NOT to push it,.. became it not being on yet :P, otherwise you'd press it far to often just to change weapon again or something.
Not saying i got it perfect, i change about settings quite a bit play testing, and most of all I'm really grateful that you WANT to press it more, as that meant it was offering something exciting and interesting to the player.
Thanks a lot for the feedback, I really appreciate it!