Seems like you can never guess what is going to affect a daylily! Some aren't bothered by anything, and others are bothered by the slightest thing. But, my experience has been that they'll do just fine. Hopefully someone else will be able to give you better information so that you don't have to worry so much. I do understand the stress though! If you aren't dividing your seedlings, I can't imagine that they would be affected by this, but I'm not a professional hybridizer.