Try "localname/" instead, though that will try https by default with my settings.
As long as your local names aren't changing all the time, an easy way is to create a keyword in your Firefox bookmarks, for each local host. That's specifically a keyword, not a tag. You can edit them in the Manage Bookmarks screen.
One nice feature of this is you can give a more complete URL for each keyword, for instance typing "nas" could link to "https://192.168.0.4:8181" with an IP and port number. It's instantly fast, and doesn't rely on a functioning DNS server.
The about:config dark magic you're looking for should be `browser.fixup.alternate.enabled = false`, `browser.fixup.dns_first_for_single_words = true` and `browser.fixup.domainsuffixwhitelist.<localdnsname> = true`.
Hope it works for you.
Yes, please. I have a separate address bar and search bar in Firefox, and it still insists on searching DDG for local hosts names when I type them in the address bar. Stop doing this. (The solution for now is to type http://localname/ )