Did you try the field at the User Menu tab where you may enter any given URL? I am realizing (only now!) that the title of this field is misleading, as it says "Rewrite the Edit Profile URL" whereas it does rewrite the link over all of the items: Howdy (in the Toolbar) and User Menu items, and not only the Edit Profile. I'll adjust the description of this setting for next release.
I understand this is not your request, but if you want different URLs over ezch, and you know how to add code to your theme's functions.php, you may use filters, as described in the Dev Guide, first section.