do i see , slow release fertilizer , have you used before , it can be a pain and can burn plants depending on how strong , some 9 month feed soils will burn cannabis over a few watering's , then it gets hotter and hotter ( just a thought )
Seedlings are very timid and can't handle things that mature plants can...The same as with any baby in the natural world.
Too much too soon will certainly have adverse effects on little ones, light, nutes, over watering are all things we shouldn't do with seedlings.
I mean, you wouldn't give a baby stake, right? Same goes with baby Cannabis plants, nutes are a bad idea until they start to mature and gain a tolerance for them. Same goes for light and water, a little bit goes a long way.