Serious question; not trying to be a smart-alec, but do you really mean a few cents?
I ask, because a dime would be ten cents, which is getting to the point where it would start to sound noticeably out of tune.
Interesting review, by the way. I’ve wondered about the String Butler before.
If you lock the string first,
either by the "luthier's knot," see the video above
or
By locking tuners...(like the ratio locking tuners...)
2. Then follow the lock / stretch / re-tune procedure in post #19...
The string won't slip out at all, even by a few cents. It will be solidly locked at pitch.
If you use the string butler...
if you use locking tuners...
if you use the luthiers knot...
Even if you use a "locking nut..."
These 4 things alone are NOT enough by themselves to stop the strings from slipping out of tune.
You must combine lock / stretch / retune (post 19) together with any of these 4 methods,. to effectively stop the strings from slipping.
It has been said that: Gibson contains an "inherent defect" which causes the G string to slip out of tune.
That is pure BS.
It's ALL about how the string is installed, that's the only cause of the problems.