I'd be interested in a link about low E coatings that depend on the sun angle, a quick search doesn't yield anything. Either way it's not a sufficient solution

I'd be interested in a link about low E coatings that depend on the sun angle, a quick search doesn't yield anything. Either way it's not a sufficient solution because AFAIK even the best solar protection glass will let 1/3 of the sun's heat in, which is an enormous amount when you have long summer days.