straight from 24on to 12/12 or phase em in??

I've vegged for a little over 3 weeks with straight 24hr light from seed....I plan on flowering within the next two weeks for height reasons...should I just flip em to 12/12 one day or start with 18/6 for a week then go 12/12?

Just go to 12/12. Don't overthink this fairly simple hobby.

Good luck.

I've read to transition them for a week, but I go straight to 12/12 right away. Haven't had an issue with stress.

Nature transitions and can't be truly mimicked so 12/12 is the best option if you are trying to keep it short indoors.