Flask Subdomain with Heroku and Godaddy (SERVER_NAME issues)
I suspect you're confusing Flask Blueprints and Heroku apps. A flask app (and its containing git repository, in this case) is one and only one Heroku app (a single domain, or subdomian... but crucially, only one of them).
A Flask Blueprint is a way of organizing individual sections of a single Flask app to be more modular.
To create Heroku Apps at awesome.darrellsilver.com and sauce.darrellsilver.com you should set up two independent Flask Apps, in two independent Git repos.
For what it is worth, I had 404 issues when I switched to an SSL endpoint using Flask on Heroku. All I had to do was change the app.config "SERVER_NAME" to the new "www.CUSTOMENDPOINTNAME.com" address from the "CUSTOMENDPOINTNAME.herokuapp.com" which was there previously.