Am I taking the correct steps?

Bloombuster is correct, they don't need to be removed. I'd still recommend defoliation to increase air flow, light penetration and yield. The more flower-bearing nodes receive direct light the better they will grow and produce resin. More airflow across the whole plant structure helps inoculate against pathogens and promotes efficient gas exchange at leaf stomata. Why defoliation increases yields is still a counterintuitive mystery. There are a number of equally valid theories as to why flower growth is stimulated. In any case the extra ounces of packed nuggets sure do testify to the effectiveness of defoliation techniques.

Нет, листья не нужно удалять! Растение само отпустит их, когда не будет в них нуждаться! Твоя задача лишь поднять этот лист с поверхности субстрата и вынести его за пределы места культивации! 😇👌 Растение заимствует из менее освещенных нижних уровней питательные вещества, перенося их к точкам роста и цветам! Если растение ещё не отпустило лист, значит оно нуждается в нём и рассчитывает на его присутствие! Если ты будешь удалять все некрасивые листья, велика вероятность того, что дефицит и проблемы распространяться на твои цветы, а это нельзя допускать, так как это обязательно приведёт к потери части потенциально возможного урожая! 👆 Удачи, друг! ✊😇

You are correct with your research, autoflowers can be more nutrient sensitive and therefore might not need as much nutrients as the schedule says. A good rule of thumb is: If you see burnt tips, lower the dosage, if they look deficient in something then add more. What we see here is most likely a deficiency, as Bloombuster also pointed out. I'd do it like this: Either 1. keep the same amount of nutrients and add more water than 0.5L at a time, or 2. use slightly more nutrients if you cannot provide more than 0.5L per watering session.

Thank you, @RafaelRapidos. I've read elsewhere that one should not feed autoflowers more than 50% of the nutrients (some sources suggest even less) recommended by the manufacturer. Does this not apply to BioBizz' organic nutrients? Up until now I've been adding nutrients according to the schedule you provided (maybe a little less).

I'd remove the lower leaves, keep the water at PH 6.5 and follow the feeding schedule provided by BioBizz. See Feeding schedule here: https://www.biobizz.com/wp-content/uploads/2020/03/Nutrient-Schedule-EN-2020.pdf

Thank you. Should I remove these leaves?