Awesome. Thanks for taking the time. Glad to understand all of this better. I feel a bit silly now meticulously going through and changing all of my "0.9.3"s to "0.9" in the past, but at least now I know better.

You're welcome!

It is true that, if the change works on z < 3, you are expanding the possible set of versions a bit, so it's not useless; one could argue that you should only depend on z != 1 if there's a bug you want to make sure that you use the versions past when it works, otherwise, no reason to restrict yourself, but it's not a big deal either way :)