Alright, I started using ZSS all of, erm, 25 minutes ago. And I searched for this and couldn't find it, so lemme describe here. When you SH and charge the stun, there is a time right before, or during landing, that will release the stun without the noise. Thus allowing you to shoot another one immediately after it.
If this is common knowledge. Oh well, I've found to many Yoshi techs anyway. XD
If this is common knowledge. Oh well, I've found to many Yoshi techs anyway. XD