I was trying to dig into this deeper, but I couldn't find any useful ways/hooks to add a little disclaimer above the Additional CSS code editor in the Wordpress Customizer. If anyone has a starting point of how i can add something simple like that, it would be greatly appreciated.
The section I am talking about is
wp-admin > Appearance > Customize > Additonal CSS
We basically want to add a disclaimer to our clients about using that section, and I wanted to do it the Wordpress way, and not hack anything using jQuery (to add it) or in core.