Import new Firewall Rules with xml import - old settings will be remain?

Hello,

I create a lot of new firewall rules on my testlab virutal Sophos XG Appliance.

Now I did an export only of the firewall rules and tested it on the same fw to import again. Before the import I deleted the rules on the fw and then I made an import and it worked. Alle fw rules are imported again.

Now I want import that rules on productive XG FWs. The XG FWs are different models with different firmware versions.

My question is, could there be any problems if I import that rules from a different XG FW to other XG models with older firmware versions?

Or will that be no problem because the xml entities, respectively the tar file with the contained xml file, is global for all XGs compatible?

And is it safe that during the import the old configuration will be kept?

I dont wanna loose some settings on the productive fws after the import.

Thanks and regards