Please could you clarify why you mentioned anonymity here, since I was speaking about one standing out, i.e. become more fingerprintable, when you add a custom filter list to Brave’s adblocker? Also, apologizes for the late response, I was very busy.
In regards to it “improving privacy,” yes, I partially agree with that—it removes some trackers. However, it makes you distinct from other Brave users and thus decreases privacy; essentially, fingerprinters can distinguish you from other Brave users more easily.
Additionally, I’m unsure in how Brave’s lack of anonymity can adequately justify adding filter lists, which has a risk. (For this example, let’s say it doesn’t make you stand out from other Brave users.)
Now, you may disagree and repeat, “That’s why it’s important for them to be trusted maintainers.” I mostly agree with this as well, but remember that there is a risk of supply chain attacks. Quoting from PrivacyGuides:
A contributor or employee might first work their way into a position of power within a project or organization, and then abuse that position by adding malicious code.
A developer may be coerced by an outside party to add malicious code.
The above mainly applies to application security, but it can also be applied to filter lists. Why? It’s due to the fact the issues above can happen to any filter list, if you contemplate it. To mitigate this, though not completely, one has to be careful with what they add. As a result, this is another issue of enabling another filter list on Brave, or adding a custom filter list.