Not really -- as mentioned prior, the reason this is impossible is because the redis database doesn't usually live in a place that is readable by NodeBB.
There are ways to dump Redis data into JSON, so all is not lost.............
Has anyone tried to backup site 1 and restore to site 2? Besides copying over the rdb file, does nodebb store anything else in folders that should be copied over to site 2?
public/uploads folder as well for uploaded files.
@baris thank you! I will give this a try.