So I guess I'll take a moment and plug my email provider, Fastmail. Their integration with 1Password to enable creation of Masked Email at account creation time is really fantastic! I have several hundred of these at this point, it's made my digital life appreciably better.

But to the point of forward-in-only -- I use the fastmail web client and iOS client. Both of these respond using the Masked Email address if you choose to respond to an email. In fact I can choose any of my masked email addressed as I am composing mail to initial communication from that address.

In short, "it just works". I really can't say enough good things about Fastmail!