Drow only glow effect if entity.isCulled.

I have no clue what you mean by that.

This will increase fps due to disabling the rendering of useless parts (Hand item texture/model, armor).

The outline requires rendering the player. I don't think there is a point in trying to "minimize" the amount of things used to render the outline, as this happens relatively rarely, and would just look like a bug when the outline changes(and the performance gain would be next to none).