2x2x54" how soon to flower?

You should have more then a week left if you want a bigger plant and yield. Longer you hold out bigger it gets. Plus your plant has not reached a maturity level. Usually 8 to 12 weeks is a vegging maturity window on photoperiods. Good luck and happy growing 🌱🌱🌱👍

It's best to assume the plant will double in height. So get it half the size you want and flip to flowering. Some plants can triple in size when the stretch finishes, some don't stretch at all. Its Dependent on strain, it's good to grow a strain a few times so you can learn the Genetics and Master growing that specific strain. I always try to get my plants half the size I want before flowering.