owner and group is changed during "lbu ci"

I tried to find explanations on the wiki and also reports on this tracker but I found nothing. I also tried to ask in chat for more explanations but still nothing, so I’ll tell you what seems to me a bug (but maybe it is not, then I’d like to understand how it works).
I’m using alpine 3.9.2, I created a user and I granted him the privileges of sudo with visudo.
So I tried to start xfce by setting one xinitrc and all start with no problems, after I added the xinitrc to “lbu include” and i restarted alpine.
It was no longer possible to start xorg by user because the whole home had become root property.

The questions I ask are therefore:

1. is it correct not to keep owner and group of a file during the backup and instead change them with the user who saves those file?
2. in this case how should I keep backups of files that are not owned by root? I have noticed that “lbu st” reacts differently depending on the user who invokes it, but it is impossible for me to make a “lbu ci” as a user because it can not mount the disk in diskless mode (mount: you must be root failed to mount /media/usb) and then anyway alpine should remember everytime to restore both apkovl. In any case I need to make a different backup from a user corresponding to the owner of the file to be saved?

(from redmine: issue id 10124, created on 2019-03-17)