One thing the PEP doesn't really talk about, and that I find very annoying is that many python linters will complain if you don't put all of your imports at the top of the file, so you get lint warnings if you do the most obvious way to implement lazy imports.

And that is actually a problem for more than just performance. In some cases, importing at the top might actually just fail. For example if you need a platform specific library, but only if it is running on that platform.