Looking like a merry Christmas indeed there prez. I wouldn't be concerned with the lower leaves at this point. They're gonna start yellowing and dying from here on out til they finish. Just using up every last drop until they die. The ones with yellow tips could be a small nute burn. If they were floppy and yellow and this was earlier in your grow it could possibly be a N def but again this late in your grow I wouldn't be that concerned. Your plants look stellar bro. Not much longer to go.