They look very nice and chubby

I like chubsters
time to repot them

soon
And what is growing in the middle?
I mean at this point I treat cannabis like lettuce or tomatoes

I will try to answer though
When they will be bigger and grow tools you will see them asking for light by raising upper fans much over proper praying position or moving away from light by changing structure to more "closed" one.
I have one that was twisting fans so much she hates LED

still grows under LED very weak comparing to the rest of them.
Then when you will be too close and overdose you will first see changes in leaf structure- it looks like streaks of neon green, yellowish veins- like leaf have a problem with turning green and pushing chlorophyll, before that leaf becomes kinda shiny- starts with the edges.
It doesn't look like bleach for some time and it's easy to see it in the natural light- so if you want to be sure and learn faster- just take them out on Sunday and take closer look

make a photo, date it, compare, repeat
It's hard to explain it properly
I am sure that different strains grow better or worse under LEDs as I can see differences even between hybrids from the same lot and the same packet

The only way to learn and check on yourself will be tweaking it, moving, coming back in two hours, looking at the plants, adjusting, coming back- and again: repeat.
Which I recommend- it's kind of funny how 5 cm can make a difference

Few hours after wake up is the best as they have faster reactions than at the start & end of the light cycle.
I am learning here myself- HPS had it's challenges but when it comes to plants behaviour in small tent area- was much more natural in my opinion and demanded less adjustments

greets