My concern is more that as a library developer I have no intention of even thinking about whether my code is “lazy import safe”. I just write “normal” Python code, and if my test suite passes, I’m done. I don’t particularly want to run my test suite twice (with and without lazy imports) and even if I did, what am I supposed to do if something fails under lazy imports? The fact that it works under “normal” imports means it’s correct Python, so why should make my life harder by avoiding constructs just to satisfy an entirely theoretical possibility that someone might want to import my code lazily?
How would an application developer know if it’s safe to enable lazy imports, without asking library developers to confirm whether their libraries are “lazy import safe”? And what happens when library authors don’t know?
Having said this, I do agree that it’s likely going to be rare that libraries won’t be lazy import safe. So maybe just assuming the best will be sufficient.