good day breedbay brothers an sisters

i have a question on seedlings an starting them
now the question has to do with starting seedlings under hps as soon as they sprout.
the reason for this is iam trying to learn about keepin plants short with out training an so on,i know theyll be some strech with the plants an if i keep them in 16oz cups all the way through to grow bloom/harvest i would like to try to do that. i know from clone its easier but if you dont want a mother plant or have room for one what to any help on the issue would be greatly need an used

thanks black