There are the following statements in the blog post about the NymVPN ad blocker:
Brave’s block list is one of the most comprehensive, well researched, and consistently maintained in the industry. It’s updated continuously as new ad networks, tracker domains, and malware hosts emerge. So it’s a huge honor for Nym and an opportunity for NymVPN users to have it supercharge their privacy. Huge thanks to the Brave team for helping us make it happen!
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DNS queries with NymVPN’s ad blocker are further protected by DoH & DoT encryption protocols so all this can be done privately. The ad blocker’s DNS queries are wrapped in either TLS (DoT) or HTTPS (DoH) encryption between the NymVPN app and the Brave list.
First of all, there should be more transparency about which blocklists are used. The article states that NymVPN uses “Brave’s blocklist,” which says very little. Curious about what the actual blocklist is, I discovered in the source code that it uses EasyList and HaGeZi Light. I’m not entirely sure how that’s unique to Brave. I am not aware of Brave using HaGeZi Light, and although I know that Brave has considered optimising EasyList, as described in this blog post, it’s only about a thousand entries smaller than the official blocklist, which is almost certainly because the blocklist version hosted on the instance NymVPN uses is older than the one hosted on the EasyList GitHub.
Regarding DoH and DoT, the wording is very confusing. It’s so unclear how that’s implemented that I’d like to see a proper technical explanation.
Finally, my request: since it seems like NymVPN uses a full-blown Brave adblock implementation (and this is one of the best cases of its use, although I’d even say it’s somewhat overkill, but that’s not important), why not add an option to use custom blocklists? One might prefer using OISD, HaGeZi Pro/Pro++/Native Tracker, or even BadBlock. Also, adding an option to add custom rules (such as a blacklist and a whitelist with support for wildcards) will provide much more freedom of customisation, as well as the ability to whitelist domains whose blocking results in breakage.