To me, drooping clawing leaves could be sign of too much water. Some nutrient disssolve easier than another. And I also had magenesium issue. So, I add a spoon of Epsom salt to a gallon of water and molasses to feed plant root once a week.
I don't worry about pH. Most fertilizers are useful in wide range of pH. Two in particulars are troublesome. Iron is better at lower pH. More over, iron is an imobile nutrient. Feeding iron to soil won't hel[ much. Then, the easiest way for me is to spray iron sulfate to leaves every couple of weeks until flowering.
Another difficult nutrient is molydinum. Plants do not need much. So I found seaweed with molydinum content and spray those to my plant during veg as well. But I spray sea weed on different day than iron.
I try to be as organic as I can. And I feed my plants mainly with earth worm casting, molasses, seaweed, and compost tea. However, I do add Epsom salt and Iron Sulfate salt to help with defieciencies. I live in a "developing country" and get my fertilizer mostly straight from smaller farms at good cost. This may not be the case for most people.