No, you just need to put it into a search path of Pd. If your goal is
to test whether the most recent change works (creation of the user
specific folder), then you obviously can't use that, you may put it
into the application specific folder (don't know the exact path for
Mac, something like /Applications/Pd.app/[...]/extra).
Download this file:
https://raw.githubusercontent.com/pure-data/deken/master/ deken-plugin.tcl
Save it to extra, make sure it has the name deken-plugin.tcl.
As far as I know, the 'remember the last path' feature hasn't been implemented yet.