Generally, we have the latest version on APIs e.g. /v4/ Once a /v5/ is released, with grace period of say 60 days, and users want to use it immediately, they can overwrite the base-domain in the ConnectorAuth.
Next, we will inform all customers about the upgrade to /v5/ and any potential breaking changes. Additionally, we ask them to move their connectors to the new version. Once we see there is either no negative interference or all customers upgraded, we change our primary connector version to /v5/ .
If a change only concerns individual endpoints, we either inform customers and make the change immediately, e.g. if the API just changed without notice and is unusable otherwise or create a separate action with the new endpoint details and run both in parallel for some time, until all customer's flows are migrated.