Ok so I have this big fan leaf showing issues. The...

Sorry but no, it is not N deficiency. If you look closely you will notice that it is interveinal yellowing (the veins are dark green and in between them the leaf is yellowing) and that's a classic magnesium deficiency. That can have 2 reason: the first and most obvious is magnesium deficiency because of lack of magnesium (not likely since you are feeding cal / mag) or due magnesium lockout due either P or K toxicity (both when given in excess lockout many seconday elements, magnesium among them). Looking at the feeding strength of your current (and past) weeks I can tell that you are feeding really strongly for soil; that your leaves are dark green, have some burnt tips and clawing (leaves tips are facing down) also shows nitrogen toxicity. Also the top leaves have really thin blades, that's another sign of either p or K toxicity. for future reference I would try not to go over 1.4 to 1.7 EC in flower adn feed no more than once every 5 to 7 days. For now stop feeding altogether and let the plant consume the excess nutrients present in the soil and its own stores, do not feed gain, you are too close to harvest (1 or 2 weeks I would say).