They are a three mode button.
Off-normal-hi it cycles.
A point though.
Npcs don't care, they see you no matter what.
You can be pitch black in the pitch black.
An anaconda flying over you will still nail you with plasma's and rails at 1k+ if its triggered into engage mode.
Hey I'm Thor -
People call me Bob.
Rule 1: Pillage. Then burn.
Rule 2: No such thing as overkill, as long as there are reloads.