What if you simply changed all your accounts to use a + variant (e.g. johnsmith+official@gmail.com) and filter out everything sent to you without a + in the address?
I’ve learned that there are a lot of places that auto remove the +official (or whatever you have after the + sign). I assume there is a common email library out there that auto strips this information.
Perhaps adding dots then? They shouldn't normally be stripped, but are also ignored by gmail. john.smith would obviously still get a ton of spam, but something like j.ohn.smith might not. (If we were literally talking about the name John Smith I expect it still would, but for other names that should work...)