How much control is local from a Homey Pro or Self Hosted server?

Well, lately a lot of us have discovered what problems an outage of Athoms servers can cause:
https://community.homey.app/t/incident-service-degraded-integrations-and-api-20260124t10h30-cet-was-homey-cloud-is-down/

Also, Athom choose to never explain what happened there…