time to correct a maour misconception.
pandas lesson of the day: why you shouldn't spread creep in zvz
notes: zerg units gain advantage from all creep regardless of the source, ergo enemy units on your creep gain everything you do from all the work you spent spreading it. in a match with few viabe options for mobile anti air, the need for creep vision is fairly limited.
by not spreading your creep you guaruntee yoursef a concave advantage in a fight because you will always be fighting at the edge of your creep. your units will form concaves faster, your units will reposition faster, your units will naturally unball faster. all of this ultimately results in more of your units firing before his units are in position to fire and this initial damage will be fairly focused on the front of the slower ball.
the further your creep is spread, the less likely you will be in equivalent position as your incoming opponent. by spreading creep you are surrendering a natural zerg advantage! you better have a good [map related] reason to do it because you arent just behind on larvae.