I definitely was thinking you were thinking the acrylic shoebox for keeping the cultures, as opposed to housing the culture containers. The only time I had escapees was when a maggot would crawl through the container vents; that rarely happened.
I think if you can get a substantial springtail population, you might be able to get away a week without feeding if the situation arose. I did it because I like having as much of an ecosystem as possible; whether or not it benefited my frogs, I haven't the slightest, but springtails are easy to keep