In your FAQ, you say:

• You cannot reply from the + address: your real email will appear as the sender.

It is absolutely possible to send an email from a + address

However, it is not immediately possible to "Reply from the same address to which the message was sent", without it first being added in the Accounts and Import Send as options.

If you add an email that is the same as yours, it gets immediately approved without verification.

I am not arguing the other drawbacks of this approach. It still is not very privacy oriented.