It could be interesting to rename PDF in case you decide to change pattern of your bibtexkey, but leaving some personnalized text. Maybe in the cleaning option?
Example :
Perazzo12_R_pathophysio.pdf
will become
Perazzo12_WJHep_R_pathophysio.pdf
I was able to do by a script which I run as export on all files with pdf already linked (old bibtexkey). The script is personnalized, so it search for _ and append for journal. I just run this file in command line (I'm on Ubuntu).
renamer.sh
\begin{file}rename -n 's/([^_]+)(.*)/'"\format[FormatChars]{\journal}"'$2/' \format[FileLink]{\file} \end{file}
That functionality should be put into "Cleanup Entries"
There is already a "Rename PDFs to given filename format pattern" under "Cleanup Entries", so this feature request can be closed.