Years ago, I proposed that default image ordering be eliminated. It's often confusing, and tends to produce unpleasant surprises. The initial response was to change the order to Custom if the user took one of a number of different possible actions. This cured some of the surprises, but it has, in turn, crippled other functionality, like being able to sort folders without affecting the order of the images at the same level, or being able to move the folders in front of the images (other than by clicking and dragging them).
It's time to update this feature request, now with the benefit of many more years of experience.
Remove default image ordering. All album objects (images, folders, whatever) remain in the sequence they were in when added, unless the user chooses to change the order. (This is my Don't do me any "favors" principle in action.)
If the Add menu is used, or if New folder is selected, place the new objects at the end. If objects are dragged into the Explore window, plant them wherever the user drags them.
If an entire folder is dragged in, leave its contents in name order, which is what the OS defaults to.
If no objects are selected in the Explore window, the context menu should include a Folders first option. It should not reorder the folders or images - it should just move the folders to the top. It might be nice to offer a Pages last option, as well, though that gets a little confusing since some skins reorder things like pages in a way that doesn't match what one sees in the Explore view. But it would still be nice to be able to keep them together, for ease of project maintenance.
If no objects are selected in the Explore window, the context menu should include the option to sort all of the objects by name, modified date, date added, camera date, etc.
If any subset of the objects is selected - either a contiguous group (click, SHIFT-click) or a non-contiguous group (click, CTRL-click) - or if all of the objects are selected (CTRL-A), the context menu should offer to reorder the selected objects by name, modified date, date added, camera date, etc. This reordering should not affect any objects other than those selected.
For camera date sorting, if an object has no camera date, the sort should use the file modified date (or perhaps the file created date?).
Objects added after any reordering is chosen would not be affected unless the user selects them and chooses an ordering method. In other words, no user action should create a new default order that would apply to objects added subsequently.
In putting together my "family" album, for example, I often have to deal with a mix of images that have camera dates and images that don't. The file dates on the images are of no use, since I may be grabbing images that originated in 2013, but I'm just glomming onto them now. The fact that the file date is 2018 is worse than useless, since it produces entirely incorrect results. So, I often need to be able to select only the images that have camera dates and sort them, without touching any of the surrounding images. Currently, jAlbum makes this almost impossible. (BTW, I hate Facebook - when you upload images, the metadata get dumped, so the camera date is gone, and the file names are random.)