I usually ask people to at least read this one page [1], not to convince them, but rather just so that it is understood that the extension is fully configurable: it can be at any point in the full block-all / allow-all spectrum.
[1] https://github.com/gorhill/httpswitchboard/wiki/How-to-use-H...
I just added a 3rd example of how the extension can be used without blocking anything, while still reporting everything. If anything, this can be useful to keep the other privacy extensions open for scrutiny.