After the wiper does its thing, the resin evens itself back out over the tank. It seems like the build plate is almost going back down too fast? The resin hasnt leveled itself back out evenly before the laser starts again. Is this normal?
If I understand correctly, yes it is normal. Remember, we print on the bottom surface of the tank. You only need 100 µm of resin to print in any one place. Wile the tank may look dry locally, it should not be: the wiper leaves a thin coating.
Also, as a layer finishes and it lifts up there will be some resin that will remain on the underside of the print, more than enough for the next layer most likely.