Yes. I made the mistake of setting up Google Home with my “Google Apps for Your Domain” account I used since around 2009. Now I’m married and can’t add my wife. It’s been years and no changes: it still doesn’t work.
My wife texts me each time she wants me to make the robot vacuum cleaner to do it's thing since you can't have multiple accounts and the backend bugs out when you switch devices to login from.
My partner and I have found that us logging into multiple devices with the same account is much more supported. We have a shared password manager and email router setup. So us@domain.net gets forwarded to both our gmail accounts. I have the "send as" feature setup for us@domain.net as well.
So we effectively have a custom domain in gmail, for sending and receiving.
As far as the internet is concerned we are one entity with multiple devices.
Welcome to the future :)