Gibson standard models have Gibson binding if it's a guitar that historically had binding and Gibson binding always has the nibs. I love them, so smooth! I'm not hard on frets so a refret will be someone else's problem.
Well then I'll just make sure anything I buy used has a lot of good years left on the frets and not worry about it.
A stock Gibson nut should handle 11s no problem and likely 12s.
Fingers crossed that 11s will be enough to get down to A#. I'm not after big strings for tone, I just want to find what size it really too small at that tuning, then go one size up from that.
EDIT: Regardless, I always just try the strings I want to use without changing anything but the setup. I'll just adjust action for optimum sustain and minimal amplified buzz, make sure the heck is as straight as I like it, then after 24 to 48 hours at my desired pitch, if the neck hasn't moved I intonate the guitar and live with it for awhile. I don't like to do more work than is required to an instrument, even with electronics I will spend up to a tear with stock parts before I'm certain I feel dissatisfied, then I really think about what I'm missing and how to get it. I'm really fussy about guitar tone, but if I get used to something then it's fine. Why out mire thought into it? If something keeps bugging me more every time I play a guitar then I get out my tools.
I took the same approach with my bass. I'm not somebody who has a pre-baked list of things I swap out on an instrument on purchase-day, I just go by what my hands and/or ears are still bothered by after many many months. If that nut can handle 12s (maybe), then I'm sure it'll be fine. I just remember reaching that point in my Dick Dale phase in high school where I moved up to like 12.5 or some other stupid he-man size, and the nut slot for E was not having it.
... but I liked it, I wanted even more string beef... and so that was my last 6-string... it's been all basses since then.
Maybe I'm destined for a baritone...