Stretch

How long into 12/12 do most continue to stretch after a normal veg?

at varies a lot from strain to strain and not only that but depending on phenos to.. what strain are you growing?
there is also a lot of other variables you have to take into account.
i think you can stunt stretch a but by using far red lights (730nm). not 100% about this tho..

but most strains will stretch 2-3 times...

Strain dependant. Just expect it can be double or triple size.