While it seems a good initiative, it riddles too many question if privacy is the main focus concern. Admittedly it a hard thing to do and very difficult to strike a balance and in no way I'm targeting anyone/anything in personal way, but here're my two cents:
1. Like any privacy centric service, it really still a 'good faith' putting up front. Example 'user data that shall not be logged, it is discarded as quickly as possible' - who decide what type type of data shall not be logged? I would personally rather have a master 'completely no logging' option. I know under the faq 'Some features require some sort of data retention. In that case, our users are given the option, control, and full access on what is logged and for how long' may have clarity for some people, it still riddles around 'good faith' IMHO.
2. Despite the claimed crypto currency support, but E-mail based login only.
3. Surprised to see Hong Kong is up there in the Hardened Privacy mode. It true HK has PDPO similar to the GDPR, but it much less refined as it doesn't define clearly of the accountability and governance, no prior consent, no mandatory breach notification, etc. And not to raise anything, but I think the situation now in HK is pretty self-explanatory to put anyones imagination as to the potential regulation changes in the future.
These are just the few and most upfront ones. Hope NextDNS can improve and strike for a better balance.