The Auto Buff Gem

I didn't misread it. I bolded the question because it's nothing relevant to the Auto Buff Gem.

I don't really see how it's irrelevant, if you can assign a skill to a macro, then you can also assign the same skill, that is, the skill, not the macro, to the auto buff gem, given that it has no damage reflecting properties.

It's a simple criterion that's easy to test in game, and allows one to check without having to look through a long list.