you are scared of having the light too close and than decide to go for a full 24h light cycle?
I would suggest you to give a look to the concept of DLI and how much photon/light/energy can the plant process in each of the stages of her life, to my memory is something like
seedlings are ok with less than 100 umoles/sec
Veg somewhere around 300/600 depending on so many things and style of grow
flowering 800+ after the 1000 you have to supplement co2 not to trow away photons/money
I know it's hard to get the right distance and have the led on that sweet spot where you have balance between heat and umoles spashed on your canopy, try get some ppfd data for the model of your light will help you to guess a lot better, whitout a proper quantum reader it's all guessing and trying anyway!!
I want one of those!!
peace!