With any upgrade, the advice is start by saving a ZD backup file and add digits to identify the version you saved it from.
Then, check the Release Notes for the version you intend to upgrade to, and confirm that all models of AP you have are
supported, and that you can upgrade from the version you're currently running.
Part of the ZD configuration is the mesh ESSID and passphrase, which will be the same after your upgrade, allowing those
Mesh nodes to eventually all get upgraded.