Lyman Customer Service
Thanks for the inputs.
I posed the same question to Lyman Customer Service, and they responded almost immediately: "The spray lube, once applied to the cases, should stay on for about a day or 2 and will evaporate if left much longer than that."
Good to know, so that when I'm working on a batch of 200-300 cases, it's okay to interrupt at any point, like for dinner or overnight.