Hey Mike,
I'm not sure about your specific setup, but I assume you are using the
django.contrib.auth user model and are moving it over to your own app,
and you have your own userprofile model that links to it. The user
model in django.contrib.auth is a swappable model. Basically meaning as
long as it inherits from a base class (I believe BaseUser) and you
configure your settings (AUTH_USER_MODEL) to look at it, you should be
fine, as long as you get the user model via get_user_model.
A link to the documentation on this
https://docs.djangoproject.com/en/3.0/topics/auth/customizing/#referencing-the-user-model
The next section also goes into defining a custom user model.
But in short there should be no ill-effects if you do everything right 😉.
Also if you are moving your own user model into your own app, I would
recommend naming it something other than common, something containing
auth, like "catapp_auth" so it is clear that your user models and any
custom authorization / authentication happens in there.
Hope that helps!
Cheers,
Michael.