[snodnipper]

Having just manually enabled DoH, it is pretty tricky to see that DoH is enabled (e.g. from padlock/shield). In the end I saw the necessary flags from: https://www.bleepingcomputer.com/news/software/mozilla-enabl...

Under about:config, it seems like network.trr.mode with values 2 or 3 are good choices, https://wiki.mozilla.org/Trusted_Recursive_Resolver#network....

UPDATE: network.trr.mode with 3 is not working for me in Australia.