The situation you describe will not be a good one for your vinca.

Why would you start them so early? They have done half their life span blooming in your light setup. I'll bet your veggies are overgrown too and will have a hard time adjusting when they are set outside

Half it's life span ? Many are on their 3rd full set of leaves, with a 4th pair. I sorta *induced* blooming by testing my LED setup with the red blooming lights on. My vinca's went well into the 1st hard frost so I'm not sure how it's well into it's half life span.

The same with the Vegs. Due to the new light setup, they are no leggy or vertical. Very bushy with leaves going out 8 inches past the stem, whereas under my former lights, it probably would be at least another 6 inches+ higher.