Add in advance settings an option to alter/force a file upload filename (not extention) to change to a certain name.

When you check a zip file, the file indexation is, ID_uploudCounter_filename.ext
If the file is forced to a set name per question(per file upload) finding a file for a set question, when a survey as 20 files is much easier.

http://prntscr.com/b1jddj

Imagine that example in print, with 1000 surveys, with 10 file uploads each.
It's not easy :P

With this change i would visually see, file 001_01 is a CV, file 001_02 is a medical clearance, etc, etc, by forcing the file to change to a set readable name.
Like so.

http://prntscr.com/b1jeby

Best regards

Nuno Reis