Of course it does, nobody will take into account the special case of people who use subdomains or even just non-standard email address separators, unless they are a rather determined government agency and then all of a sudden almost no method works anymore for privacy.

I'm pretty sure even Google doesn't care about the dozens of people who use a different email address for different services.

This was my thinking here - yes, it has flaws in the approach, but it also gets me out of the main buckets that spammers will hit, and ad brokers will generally be selling.

It's a little friction, that maybe goes a long way. Pretty hard to actually evaluate though. Gives me the warm and fuzzies and I got to play around setting it up, so all good there.