Just stumbled on this really neat post on how to setup Emacs as default file manager in Ubuntu. So, why we don't do the same in EDE?

First create a script named dired and save it in known place, e.g. your $HOME folder, with this content (I found it here):

#!/bin/bash
emacsclient --eval "(dired \"${1:-~}\")"

Then launch ede-preferred-applications, go to Utilities > File Manager > Browse... and find location where you stored dired script. Test it with:

ede-launch --launch file_manager $HOME

And that's it.