I painted my front door (metal) with Sherwin-Williams Emerald Exterior Satin (Acrylic Latex) and the result is not super. The paint dries so fast that I ended with multiple brush marks and roller marks. Because of panels on the doors, I have to use a brush and a roller.
After some online research, I found out about paint additive (e.g. Floetrol, XIM Latex Extender). According to what I read online (mostly online reviews...), those additive help getting rid of the brush and roller marks and makes it easier to apply.
Have you ever tried to add Floetrol / XIM Latex Extender to your paint? Does it really help? If it helps so much, why Sherwin Williams does not add it to its paints? Thanks!