@elextr it's already in the open dialog, and I'm not gonna move anything. I'm just gonna merge Use fixed encoding when opening non-Unicode files checkbox and Default encoding (existing non-Unicode files) combo, only keeping the combo and having an additional Detect from file item in it which takes over the current Use fixed encoding when opening non-Unicode files checkbox role.
Ok, that one is cosmetic, removing a checkbox and adding a do nothing combo setting instead.
But I disagree that its the same as the encoding selection in the open dialog, the open dialog sets encoding to use for _all_ files, the one in prefs sets it for _non-unicode_ files IIUC. I didn't check the code, so if they in fact work the same then there is a bug because one of the functions is missing, or it was just described wrong and then the labels need fixing to say the right thing. Don't forget the manual if changing UI.