Then you can ask the agent to write an app for you! It can just give itself tools to do stuff with the devices or can make a full UI.
What it looks like for different members of the family: everybody has access to the same stuff. Everything is syncced between all devices and any integrations you add are available to the other people in the household. Hopefully you all like each other.
I just have the UI working with speakers, but the tool it has can do a ton, so you can ask Agent Heath to control all sorts of home assistant stuff.
Also, if you want the UI to be different, just ask :)