i personally never go more than 18 hours of light with seedlings. its not natural, and since been proven to increase males, or rather decrease females
especially in sativa dominant varieties (which im sure urs isnt but..).
there are Many "light Independent reactions" that occur in a plants life day to day- more so within a seedling that has not reached maturity yet-
simply, there are things that occur during the night that Cannot occur during day. any stress before maturity is no good, and there is arguably little evidence showing that 24 horus of light on a seedling has any impact what so ever on the rate of its growth.
what you see and take care of on the outside, is just as important as on the inside...immature plants need darkness IMO
however clones from a mature plant are a completely different story and i always keep them on 24/7 light
if you want to boost growth, stay Consistant, and stay Natural imo, either way u will be fine tho