Details in the Zulip thread.

TLDR;

retries=1 restricts the producer to only one retry in the event of transient errors. Setting it to the default (2147483647) to ensure greater resilience against transient errors.

acks=1 could lead to loss of schema-history records in case the leader goes down after the acknowledgement before the followers have replicated the record. Setting it to the default (all) to prevent data loss.

max.in.flight.requests.per.connection configuration is set to its default value of 5. For values greater than 1, in case of failed sends, there is a risk of message reordering. Thus setting it to 1.

Setting enable.idempotence to false for backward compatibility.