anytime anyone asks what the norm is in tattoo it reads like a loaded question.
the lower liner setting is probably due to the (usually) decreased point gap, which would intuitively indicate that they (liners) should run on less voltage. This is not the case however, as most zappists (whoever I stole that term from, thanks) run their shaders with a lot more front spring compression, which is where most of the 'punch' in a punchy shader comes from. So shaders tend to have a larger point gap, but run on less voltage, which sounds ,like the opposite of what they SHOULD do.
Unless you use an o-ring, or don't roll your springs, or there's too much distance between the coils and armature bar, or not enough front spring compression, or too much rear spring tension, or you were born on a Thursday, or you happen to be Chris Angel MINDFREAK! which is why it always reads like a loaded question when someone asks what the norm is. Anyone got a different take on this, I don't have a critical.