To me, that’s why the actual methodology comes into play, and is critical. I’ve never experienced any kind of nic oxidation when using my preferred method:
No breathing (in the normal “accepted” sense), no frothing, no cap off for hours etc… But, bear in mind, my liquids don’t usually make it past the two or three month mark. Maybe three or four times in the past two years have I “found” a stray bottle that made it to the 6 month mark, and while those didn’t have issue, A. It’s not enough to be anything more than anecdotal, B. They were stored indoors, at <70°F. So while I acknowledge it’s possible things could change, I haven’t had such an experience yet (and I believe it’s due to the way I mix. YMMV. 