I can see why locking tuners make string changing quicker/easier....but I don't get why some people think that with non-locking tuners, strings will "slip" out of tune....?
I've never seen strings slip, not matter how much playing/bending I do.
I always cut the strings neatly to length, do a few winds (how many, depends on the string's gauge). I only leave about 1/2" of string sticking out of the hole, and then I just bend that around the post.
I've never done any of the over/under/twist/fold "tricks" some people use when stringing....or the so called "Pro Wrap"...etc.
I mean, if the strings actually slipped...at some point the end would pull out of the hole....but that's never, ever happened, and I tend not to change strings too often, so they get a lot of play and bending, etc.
The one thing that I always do when re-stringing, is to stretch new strings quite a bit. I mean, I really work them several times, and keep checking the tuning. If I stretch a string and it goes flat, I keep repeating that until the tuner shows that it's holding tune even after a stretch. Once that's set.....they don't go out of tune because of any string "slipping".
There's other factors that could make strings go out of tune.
AFA as the G string tuning issue that many guitars seem to have...I've adopted a variation on the typical intonation process of using the harmonic and the 12th fret.
Instead I simply set the intonation by checking the tuning at the 5th and 17th frets (no harmonics). I set the bridge saddles so that the tuning at those two frets is as equally in-tune as possible. Most times I can get both almost perfect....or at worst, they'll be equally out of tune, but that's never more than a couple of clicks on the strobe tuner, and that small equal offset at both positions, allows the string to still be generally in-tune across the whole neck, better than when just using the 12th fret/harmonic approach...IMO.
The other "trick" for the G string that I've found helps is at the pickup.
If you have pickups with magnet adjusting screws...lower the G string screw by 1/2 to 2 turns. You'll have to experiment what works for your guitar and pickup.
When they are set evenly for a pickup...often the G string still sounds more prominent, it tends to boom out, and has a tendency to be or sound louder than D or B/E...so then if there is any slight tuning issue with the G, it just sticks out even more because of that.
The point is to slightly lower the output of the G string a bit. I find the point where the G-string output is lowered, but not so that it sounds too low...rather to that point where it blends j-u-s-t a little "under" the others level-wise, and without that typical G-string boom.
I find that helps keep any G string tuning issues from sounding as obvious.