FWIW, I put my seedlings under the very brightest light that I have available.
I have never used LEDs (other than cheapie screw ins).
I have dimmable ballasts for my HIDs but have never dimmed them.
Whenever possible (depending upon where I am growing) I put my seedlings under the sun outdoors ASAP.
Here is a seedling which popped thru the soil yesterday.
Under the sun outside today…cloudy day here…rats!
ETA:
That seedling is the only one which is viable thus far in my mass germination effort with @Scissor-Hanz notoriously difficult to germinate Head Band seeds. I used styrofoam egg carton cells in order to maximize the number of seeds in my attempt, using the least amount of space and smallest quantity of seed starter mix