Lookin great! As far as the size of the buds, remember, you likely won't see the same type colas you're used to, but you will instead see many more buds that are of medium sized and almost no small ones.
The stems on those plants look very healthy, and as far as the deficiency goes, I'd just bump up your nutes a hair. But I am not good at these kinds of fixes.
I think you're gonna be really surprised how much bud you have there. Also, I think the scrog tends to make it take a little longer in flower, so I definitely wouldn't sweat anything yet.