Node diversity isn't optional. It's the whole point.
Bitcoin Knots has, for years, been the second serious full-node implementation keeping Bitcoin Core honest. With the RDTS (BIP-110) network upgrade, Knots' maintainer chose to fold RDTS enforcement into every future release — and declined to continue maintaining a non-RDTS branch.
That leaves Bitcoin, in practice, with one actively maintained node implementation. One client, one roadmap, one point of failure for the entire network's software diversity.
Bitcoin Untangled is a continuation of Bitcoin Knots, forked from the last non-RDTS release, tracking Bitcoin Core's ongoing development independently — without the RDTS branch folded in.
Not a rejection of RDTS on principle. A refusal to let node-implementation diversity quietly disappear because one maintainer changed course.