[DiapDealer]

I don't think you're missing anything. It has always been my opinion that anyone wanting additional modules (other than those included with the official bundle) should simply use an external python for plugins. We don't need a functioning, relocateable pip in our bundled python in my opinion.

EDIT: if you're asking in regard to the neiss/python-appimage project, I think the notion is that you can extract any of their appimage python versions, install extra modules with pip and then package it all back up as an appimage again.