Used Headphones to Watch a Show...

[Michael Leigh]

But basically it always depends on the volume and not on its source.

Unfortunately I do not agree. As I've explained in many of my posts. The headphone drive unit/speaker is so close to the ear, even at very low volumes can irritate the ear for someone with "noise induced" tinnitus and possibly making it worse. It is just not worth the risk in my opinion.

Michael

 

[Tinniger]

The headphone warnings seem to be a special quirk of yours.
You would probably also warn against headphones if the speakers are off, and they are actually not headphones, but ear protection capsules.
If you warned against moderate volume over headphones, and not against any headphone use (even at low volume), I would be with you.