I have a blue light filter on my glasses. I opted in because I sometimes use screens close to bed time for work.
I’m not going to tell you they work better then a placebo, but they work as good as one, and that’s all I need.
They are 100% yellow tinted. Anyone who tells you they don’t block blue light is a liar.
Those are rubber grommets. They’ll protect cables from wearing on metal that pass through the case.
Likely for things with hard wired controllers, like fan controllers or led lighting. You can hang the controller outside of the case in the back where nobody will see it.