Just a quick update to note that we added the new preferences in Tropy 1.4.2.
In the preferences window, you can now decide into which field the filename (without extension) should be written. You can pick a field at the item- and the photo-level (if you don’t want to import the file name at all you can do so by clearing the respective selection).
By default, data embedded in the photos (e.g., Exif, XMP, or IPTC fields) will always win. That is, if you normally save the file name as dc:title but the photo embeds dc:title the embedded value will be used by Troy; there is an additional checkbox to to indicate if, instead, you always want the file name to be used.
So you should be able to solve the issue above now by either saving the file name to a different field, or by saving it to dc:title and overriding the embedded value.