My Duetwifi is installed in an all aluminum electronics enclosure with a polycarbonate hatch in the back.
As you can imagine I only have a good signal when the printer is oriented so that the back is directed to the antenna of the router.
To cover this issue, I installed a separate AP behind the printer. It is a heavy one, so I don't move it easily. Just rolling it around on a couple of sqm for easy access when tinkering…