This is more a quality of life thing for more accessibility to potential deaf players or even just people who mute ZC which is pretty common. I think relying simply on sound design to alert the player when the sword is charged up, especially when you have items and an editor that can alter timing, might be a bit of bad design on the engine's end. I think it'd be ideal to have an option to make the sword flash when it is charged. As for the Hurricane Spin charge, that's where I'm at a loss. But perhaps we can spitball some ideas if this is considered?
(I guess this goes without saying, but the same thing would work for the hammer. I don't think there's anything else that charges up, right?
Edit: Oh! Sword tapping to find a bombable spot. Maybe if we're going far into the request, there can be a spark graphic as visual aid?)