Master (left) is the default as already stated. Probably, it's nothing. However, I think you are within your rights to get a knew one. It wasn't setup correctly at point of purchase.
A minor detail. But not a minor expense.
If it were me, as it's new, I would spend a few hours stress testing it with everything (except furmark - a bit on the edge that one). Then I'd set up a good custom fan profile, or a fixed one at around 65%. Add 55MHz to the core. Overvolt via MSI by 25% (That number is mis leading - it goes to 100% but 1080 dont run at double voltage) Leave memory as it is. And put the power to 110% temp 87c.
That seems pretty random I know, it's just a kind of moderate/slightly heavy OC. I reckon if you can pass Firestrike stress test extreme (loops graphics test 1 20x - takes 10mins) on both stock and that OC, plus running heaven and anything else you may have like valley you are looking good.
One thing. I never game at default fan settings as the backplate gets a bit hotter than I'm happy with under the memory/vrm area. For stock tests, to be safe I'd say set fan to at least 50% - for me it would be 60%.
In an airy case with air moving over the backplate, plus raised fan this problem seems to go away, no black screens or other things that some have reported.
It doesn't belong in this thread, so very briefly, I mention back plate memory heat as there is an on going "issue," with some EVGA pascal cards literally smoking and catching fire in that area. I suspect it's a minority, a small minority, but I have never owned a GPU with a backplate that gets painful to touch.
Anyhow. Totally your call. But due to that very small issue of BIOS switch postition I would be very careful to fully test, and check what does, and what doesn't void warranty.
Good luck!!
EDIT: I should add. I tried that sample OC above, and it works fine without any voltage change, so you can forget about that if you wish. The only thing it changes is that with the voltage up by 25pts (I say pts because it can't possibly be %) the boost clock stays higher for longer, but max is the same.
2. I said not to up the VRAM due to an ongoing issue (NOT FOR THIS THREAD - I know mods.) about a
possible heat problem.
Nothing definitive yet, and seems to afftect small % of cards.