In MySQL, the notion of cursorFetch is directly associated with whether or not the user configures the snapshot.fetch.size connector configuration. The connector will use the text-based protocol to resolve temporal values when omitted. When provided, the connector uses the binary-based protocol.

See https://debezium.zulipchat.com/#narrow/channel/302529-community-general/topic/MySQL.20TIME.20as.20duration/near/482350765

I should note we had a similar situation when implementing MariaDB and we opted for MariaDB to simply have a singular text-based protocol implementation of the AbstractFieldReader contract.