Problem/Motivation
Currently containers are marked as inline containers by applying container-inline class. While this might work fine for some use cases, there are use cases where other changes might have to be applied to the markup based on whether it's displayed inline. For example, inline error messages might be displayed differently.
Proposed resolution
Instead of using the container-inline class as an API, provide explicit API for marking containers inline. We could still apply container-inline class internally to those elements.
Comments
Comment #2
huzookaContainer-inline usage research in core with an older codebase (8.7.x in February 2019) here.