Appian 25.3 to 25.1 downgrade

We recently upgraded Appian from version 25.1 to 25.3, performed some testing, and created new objects in the latest version.

Now, we want to revert to version 25.1. However, we did not take a backup before the upgrade.
Is it possible to restore the previous version without a database backup?
When attempting to downgrade to 25.1, we are encountering data synchronization issues during Tomcat startup.
As a workaround, can we manually revert individual object changes and delete the newly created objects before downgrading?
Please share your suggestions. Your input is much appreciated.