Mullvad also has DNS with different kind of blockers: https://mullvad.net/en/help/dns-over-https-and-dns-over-tls/ And for the DNS blocking you don’t need an account.

I use the same. In the Lemmy PWA I can just swipe right from the left side of the screen and this works as a back button for me.

Yes it does. You can follow BookWyrm accounts from Mastodon and Calckey. At least that is what I tested.