Yes, so the plan is if you deploy a pre-defined App from the “Store” those will be static and not let you make direct YAML edits. This is to protect the upgrade path from blowing up on you later as the App Catalog moves forward.
If you deploy a manual Docker/Compose App via the UI or by supplying a YAML file, you will then be able to edit it later in the UI (or CLI) by changing the YAML directly, as you would with a traditional docker compose deployment on any standard Linux.