WeakAuras 2 Addon Help

Hello, I'm trying to use WeakAuras 2. What I want it to do is make the spell icons disappear on cooldown and then slowly fade completely visible when they are coming off cooldown. I can get the icons to disappear and come back to being visible easy enough, but I can't get it to fade properly. All I can do with the fade animation is fade in the beginning right when I use the ability or after the ability is off cooldown already. I first tried version 2.0.8 and now I'm using Bunny's Weak Auras from this link here:

https://forum.warmane.com/showthread.php?t=439253

While definitely an improved version, I can't seem to make it do what I want. Maybe there's something you can do with the Custom Function script? I tried looking this up but couldn't find any good information on how to use it or its purpose. Maybe there's a different version I'm missing, or even a different addon to try altogether? (I don't want cast bars, I'm going to stick with icons either way.) Any help or suggestions is appreciated.