> ... jemalloc can reduce memory usage ...

Thanks for the tip. I downloaded the source and successfully built the DLL, then went looking for a way to get it loaded. Unfortunately, DLL injection, which is needed to use this allocator in Python, seems to be much better supported on Linux than on Windows. Basically, Microsoft's documentation [1] for AppInit_DLL, the shim for DLL injection on Windows, says (in effect) "here's how to use this technique, but we don't recommend using it, so here's a link [2] for what we recommend you do instead. That link takes you to "Try searching for what you need. This page doesn’t exist."

[1] https://support.microsoft.com/en-us/help/197571/working-with-the-appinit-dlls-registry-value
[2] https://support.microsoft.com/en-us/help/134655