Pressing either "e" or "l" in dispatch conf does not have any effect. I haven't tried others because I did not want to mess up my config but I suspect the problem may be the same. "z" and "u" seem to work.
set an EDITOR in your sudoers.
Currently, it just calls nano when EDITOR is unset: https://gitweb.gentoo.org/proj/portage.git/tree/bin/dispatch-conf?h=v2.2.27#n340
My EDITOR variable is not set although I set "eselect editor" to a value (vi). Is that a bug or possibly my mistake? FWIW, I had nano depclean'ed.