This was my first WSing season. I had great success and learned a LOT!
And, one thing I learned for next time is that I'll NOT open any jugs until I'm ready to plant them into my garden... If you think they're getting heat build inside from too much sun, move the jugs to a more shaded or indirect light location, but don't open the jug. Seems like there's some sort of greenhouse heat exchange going on inside that the seeds enjoy. This also seems to be disrupted with the opening and closing of the jug.
My rationale is an accidental observation I made from some jugs that I kept opening and closing vs. some jugs that I never opened at all. The ones in the unopened jugs outdistanced the ones I kept opening (same type of seedlings). Once I resealed the "peepers," and stopped "peeping," they caught up to the others!
Go for "jugeye" instead, and peep down the spout. Just make sure no one has outlined it with a blackie marker!