In the recipe modules the file name is set in the attachments key-value table, but we don't do any str comprehension to e.g. template in {file_stub} or so.
Additionally, in PYMEVis snapshot upload, we now search for the upstream file itself (which is nice as this includes acquisition events and metadata), but since we currently use PYME.IO.unifiedIO.local_or_temp_filename the file stub is whatever is randomly generated for a named temporary file.