Yes, you can always test it out. As long as you do not remove or add any new zigbee devices on the new system you should be able to move the coordinator/usb stick to the other machine and easily go back if you run into a problem.
For duckdns/ssl, I use the swag docker container and followed this guide
For backups, take a look at my post here. I use a cronscript and then use the default backup program in Ubuntu to create a “backup of the backup” on a google drive.