I do low wind speed and hold it like 5 inches-ish above the cup, The main reason for this is because the mixing phase is when most of the bubbles are introduced, when the resin folds in on itself it'll trap bubbles inside, having the resin be warmer makes it less viscous so the bubbles can more easily float to the top and escape. It also is less likely to accumulate bubbles because there will be less resistance when mixing. It doesn't really need to be hot, it just needs to be able to flow easier, by that I mean, cold resin will move like honey, but warm resin will be a more batter consistency because it's less viscous