Colder dough leopards more? I thought longer room temp did this, is there an explanation why colder causes more leoparding?
I'm sure there is but there is some disagreement on what it is. However, there isn't any disagreement I know of cold dough leopards more. It doesn't have to be cold all the way through either. Just 20-30 minutes in the freezer can make a noticeable difference.
To be clear, I'm not suggesting this. I don't think it's a good thing to do if pizza quality is your goal. If you just want stark leoparding because it looks good, that one thing. If you want great pizza you should be doing things to make great pizza not stark leoparding. In my experience, the best Neapolitan pizzas don't have a lot of leoparding, and the leoparding they have is not the high contrast type - rather is a much more gentle spotting on even browning.
Also is there a difference between a 2 day bulk 1 day ball vs a 1 day bulk and 2 day ball?
Mostly in how easily the ball opens. THe longer in balls, the more relaxed the dough gets. 2 days in balls can be so relaxed that it hard to open without getting thin spots. However if you plan to use cold dough, 2 days in balls may be better to help offset the tightening effect the cold has.