Kelseys Closet

I would reduce to just 1 plant and train her low and wide plus make sure that light is as close to the canopy as the plant can handle and that airflow/exchange is as on point as possible, the air exchange would be likely my biggest question in a cupboard grow. As far as nutes, it depends on your medium. If I was in that space I'd ideally like to go organic so that its as self sustaining as possible and simple to top dress. Synthetic? I use either CX or Goliath, but given likelihood we are in different countries, availability is most likely different brands. The environment is far more influential on the outcome than brand of nutes though in my opinion.

Your lights are to faraway leds need to be closer to your plants and what is your true pull watts on your leds please I have found leds need to be loads closer than other lights or slow growing times

work backward from end result... how many colas do you want? be systematic about how you get there. use a screen/netting to organize. do it the same way each time and it won't seem complicated at all. this way you don't waste time gowing things you won't use anyway... pruning higher proportion of smaller/younger growth vs older growth. you'll know you can remove plant growth befoe it wastes effort growing out... don't go too crazy.. weigh benefits of good aiflow vs cramming it full to the brim... if you consistently use a good chunk to microbial growth, it's probably not maximizing the space.