well I'm not exactly sure, but the way I understand it is:
- if you "pip install bts_proxy", it will get it from PyPI, and if not there, it will fail
- you can get it from github, but you have to specify it explicitly, see: http://stackoverflow.com/questions/8247605/configuring-so-that-pip-install-can-work-from-github
- if you "python setup.py install" from a local git clone, it should just get it locally and that's it
Not sure if that answers your question, though...
That's also one of the reason I wrote the proxy as a separate project and not as part of the bts_tools, so that it's smaller and easier to review/audit, and hence it can be trusted easily.