SDK: catalog:findPhotos() - how to sort photos with user order?
I need to process photos of a collection or a folder in sequence of their manually arranged "User Order".
catalog:findPhotos() uses a sort argument which is documented as
- sort: (optional, string) How matching photos are sorted. One of "captureTime" (the default), "fileName", "extension".
This is only a subset of the sort options available in the application:

Trying to use assumed argument values, I found that the following options work:
- sort = "addedOrder"
- sort = "rating"
- sort = "pick"
- sort = "labelColor"
What did not work was:
- sort = "editTime"
- sort = "editCount"
- sort = "labelText"
- sort = "fileType"
- sort = "aspectRatio"
- sort = "userOrder"
Assuming that all sort options, available in the application, should also work for the SDK, what would be the parameter values for the missing options, especially for sorting with User Order?