zipimport has been rewritten in pure Python (issue25711). Now it is easier to add support of other compression methods. Although I don't think that reducing the size by 3-8% is worth complicating the code.

If you still need this, I think that the simplest way is importing the zipfile module and monkey patching the simple ZIP file implementation in the zipimport module with zipfile-based implementation. This can be made only after importing zipfile itself, i.e. in case of zipping the stdlib, the zipfile module and its dependencies should be stored uncompressed or with the deflate compression.