To take good advantage of DNS filtering users would have to disable features like Proton’s Netshield or custom DNS in Mullvad. This would allow to use configured private DNS. F.x. when using Rethink DNS, Controld, or NextDNS this could give a more of what is being blocked. I often find that usinig the DNS filtering of the VPN providers is rather limitted.
I wonder what your thoughts are on this.