Thanks for a very useful and clear checklist! Would you say decentralized DNS checks all those boxes (Namecoin is a thing, after all)? Why would a DNS require the notion of transaction?

I'm aware of sites that tell you whether you need a blockchain or not for your application, but they don't say what to use if only one or two of the requirements for a blockchain are not needed. What would a decentralized DNS strictly need if the notion of transaction wasn't required (but only the latest value)?