I'm trying to deploy a python/flask application to an Iris4Health container (2025.1) but running into some issues with packages and where they should be installed. 

First one if the flask packages themselves. I tried to installed the flask packages into the python external language server virtual environment, but even doing this when configuring the WSGI application in the web application section, it would complain about not having a WSGI framework. Once I created a custom container and added the flask package at the OS level, I was able to configure the web application without it complaining.
QUESTION: Is this the preferred method for adding the flask framework? (Creating a custom container with docker build using the iris2025.1 container as the base)

Second, once the flask application is running, what is the preferred method for adding packages. ex: flask-sqlalchamey, flask-session,etc  (that the flask would use)? Again, I tried adding these to the virtual python environment that iris creates (/dev/python/virtual/%Python Server_3252368016$) and then activating the venv and adding package using pip install in the venv.
I did this, but the flask application generates an error that it cannot find the packages... Are you supposed to add these packages the same way, in the base OS images via a docker build command?

Any help with this would be appreciated. i know that the WSGI stuff is listed as "experimental" but seems like this is a better way to host web apps