It’s the safest thing to do, though. If you break it, your old site continues to work. There is zero risk.
There is a topic about that. You can copy over your yml file and the let’s encrypt stuff and even see that it works by changing your local dns to point to the new server.
And if you have your backups on S3 then you can sleep better knowing that if something goes badly wrong you can spin up a new server and restore a backup in about 30 minutes.