Hi Jeronimo,
If you *do* save a backup before performing an upgrade, as we recommend/suggest,
the ZD will acknowledge that you have a config from the previous version (ie 10.0) if you
do a "downgrade" (upgrade to earlier version code) and ask if you want to use it.
You only lose the configuration if you downgrade but didn't have a saved configuration.
Hopefully, it was saved before upgrading as advised/recommended, as it would need to
be restored if config is lost by downgrading.