Charset Questions on Aurora-MySQL 5.7 as a Replica to a Aurora-MySQL 8.0 Primary

We are planning to upgrade from Aurora MySQL 2.10.2 (MySQL 5.7 equivalent) to Aurora MySQL 3.03.0 (MySQL 8 equivalent). One of the rollback plans that we are considering is having another Aurora MySQL 2.10.2 replicating from Aurora MySQL 3.03.0. It looks like this: The reason for this is that in case there are performance issues with Aurora MySQL 3.03.0, we can roll back to the Aurora MySQL 2.10.2 replica. But based on this article , we have to change the character_set_server/character_set_database settings to utf8 and collation_server/collation_database to utf8_unicode_ci because when we tried to insert data directly on Aurora MySQL 3.03.0, the Aurora MySQL 2.10.2 replication breaks with this error Character set '#255' is not a compiled character.... So after we do our upgrade and assuming we do not need to rollback, we plan to change the UTF settings of our Aurora MySQL 3.03.0 to the default settings of the character_set_server to utf8mb4 again and collation_server to utf8mb4_0900_ai_ci possibly after a week. I am worried that we are changing the default charset/collation related settings to our new Aurora MySQL 3.03.0. Is there any downside to this approach? For example, from the time of the upgrade to the time when we change back our charset/collation related settings, would there be any possible data corruptions/truncation because the default charset on Aurora MySQL 3.03.0 is utf8? We tested this and it seems there is none but we wanted to ask if people have seen any issue with this. But again, I'm not sure which is why I wan ted to ask about this.