You would need to research what each DNS provider offers. For example, cloudflare 1.1.1.1 is a generic DNS however if you use 1.1.1.2 that would filter malware, 1.1.1.3 would filter malware and adult content. Nextdns uses rules that you can create within your account. All these blocks / filters can actually be achieved if you use adguard home and filters, you would get the same desired effect.
I have just realised you are asking what the default options refer too. I would guess it's the default, so cloudflare would be 1.1.1.1 etc however I will let a dev answer that. I personally use the adguard home application and then input the relevent DNS I require as I mentioned in the previous post.
Have you tried encryption AdguardDNS? Create new account for free but lowest limit queries per month. So I paid Adguard VPN and free Adguard DNS queries per month. I mean increased numbers queries.
Using router, outside network for mobile, etc.
I can't add something like extended.dns.mullvad.net or my custom NextDNS id in these boxes below? I can only add or select DNS like 1.1.1.1 and 9.9.9.9 etc?
I know it is a thing, but DNS names as DNS server? I don't get it ...
But if you know an IP, you can click in the field and just start to type it.
The selection in the drop down is just the pre defined if somebody has no idea what is any IP of any DNS.
Sorry, my fault. I was not aware that the topic is 'encrypted DNS'.
You can set 'custom DNS'. Any IP you like. But it works only as long as this IP provides a DNS service that is supported.
And Encrypted DNS is not supported.