Can we add a feature to change the change the "hey siri" key phrase

I have an iphone, homepods, mac, as does my son and partner. When sombody in the house says "hey siri", often more than one device responds, and sometimes one will "talk" to the other and make a complete mess of it. If the devices are signed in with the same apple id, *sometimes* it seems to figure itself out, and if the devices have separate apple ids then it can get silly.

I don't see any way to control this, and it's frankly a little dumb that there isn't a better way to manage this, ie different key phrases. I get that apple probably wants to "brand" its assistant, but what's wrong with "OK siri", "what's up, Siri", etc, as alternate options?