In the link you provided,
unbound is used as a recursive resolver. I've done that as well and prefer to not use that approach primarily because I didn't like the latency associated with building my own DNS resolver. The author, directnupe, and myself have discussed the various approaches back-and-forth. As he indicates in the post, DNS-over-TLS without
unbound appears to be his prefered approach and it is mine as well.
Good luck, but in the end it should work for you.