Install pyqt via homebrew with `--with-python3` but still goes to Python 2
You are right. The formula does hardcode the python version. I have worked on an updated version, and it should be available tonight.

Also, it is safe to change the path directly in the source. However, being a git repository it will complain if you have uncommitted changes when you want to update. Your best bet would be to just wait until tonight or tomorrow morning.