ADD Spells/Runes charging -> Visual Guide

Hello, just want to give a quick Feedback about Spellcasting / Runes.

Can you add a visual guide when charging Spells / Runes at the Runesymbol on the User Interface?
What I do understand is, that you can charge Spells, right? Because the longer you hold, the bigger the e.g.: Fireball gets and there is a sound effect that notifies you.

But I do never know when it is fully loaded, so when you add a visual charging around the UI of the Runes (glow, border whatever), that would be nice and would help people to understand the casting.

thanks!