Did you read my original comment? My point was that if you're using Flask, you are responsible for pulling in all of those components and making sure they work together, not that there weren't good components available for Flask. I'd rather use Django if I need all of those things and want them to work together. If you don't have a relational database, Django's ecosystem advantage (much of which hinges on the ORM) isn't as strong and Flask becomes worth looking at again.
I haven't really used SQLAlchemy in anger since about 2009. I remember it being fine but I can't really say much else about it. That said, I haven't run into any limitations of the Django ORM that have driven me to look at other ones.
