This is an official discussion thread linked from the PrivacyTools website. This thread can be used for troubleshooting, questions, discussions and if you look for alternatives.
Currently the page (you seem to have a broken link on the word PrivacyTools by the way) warns that there are some caveats about this, but Google’s DNS page says this and I wonder how it behaves in the fixed in Android 10.
I will not be getting my hands on Android 10 anytime soon.
Hmm interesting, thanks for the heads up