Hey, that's a good question! At the moment, it treats the latest run as the desired state. So any new changes to a schema will simply overwrite the old version. I'd like to version these so people can navigate schema versions in the UI.
If using a plugins, they currently are triggered either via the CLI or a schedule on the UI, so updates will only appear in the catalog after a plugin has run.
I'd also love to have some native integrations beyond Airflow. Once I've matured the existing plugin ecosystem a bit more, it's high on my list (along with column-level lineage).