https://editor.datatables.net/reference/field/upload fileReadText can be used to control the text shown "when a file is being read before it is uploaded"
My upload takes a bit of time, and there's no indication to the user that the Create window has even accepted his file. I.e., I still see "Choose file..." during the upload. Is there any way from Editor methods or options to control the text while the Create window is waiting for the ajax response?