Sounds fair on both counts... Good news from José above that the official MSSQL support is coming soon and will be merged into ecto_sql package.... and like I said, if you (or someone else) decides they want to work on updating the old ecto2 SQLite adapter to work with Ecto3, I can't promise much, but I'd be glad to try and help!
Also, as a note, my first production Elixir service didn't talk to a relational DB at all, and was basically a thin API wrapper around ElasticSearch... others I know have basically used it just for realtime features connecting to browsers with WebSockets for push via Phoenix Channels (or now LiveView)... so even without any of those database adapters you may well find a use case it's a perfect fit for, and where lack of those adapters is not an impediment! Either way, good luck!