Not that I'm aware of, but my gut says it's not a great idea, particularly with a bottle that's repeatedly opened.Have you or anyone else tested the impact of repeateded freeze-thaw that might be experienced when someone frequently removes a freezer-kept supply to mix their DIY recipes?
My personal mixing technique obviates the need to have a "working bottle" of high-test nic, but if I did mix that way, I believe I would keep that bottle in the fridge, not the freezer.