Question on Kafka Upgrade bounces


My name is Dana, from Ethoca Inc. , Canada. I am looking through the kafka upgrade guide linked below, and am a bit confused on the bounces, it says:

if upgrading from 2.3 or below, you will need to do two rolling bounces, where during the first rolling bounce phase you set the config upgrade.from="older version" (possible values are "0.10.0" - "2.3" ) and during the second you remove it.

Do we have to keep the applications set to upgrade.from="2.3" until all the applications of our kafka cluster are upgraded to 2.4+, or is it in the context of the same application, i.e. the instances of the same application getting to 2.4+ and then good to go with the second bounce? Could you please clarify this part?


Thank you!