On with account should we set up our HomePod?

My dad and I are gonna buy a HomePod to use it as a home central. I want to put it in my room to use it as a speaker, and he mainly wants it so he can set up our smart home with Home Assistant/Homebridge. Right now, he's mainly experimenting. So, the question is, on what Apple account should we put it? Because I want to be able to use the "Hey Siri, play Example on Spotify" and play it on my account. And he is worried he won't be able to put devices in there. I don't really understand how Homebridge and Home Assistant work, but he is pretty sure that even if I give him the permission to add home accessories, he won't be able to add them with his Homebridge. If we put it on his account, can I still listen to Spotify without holding my phone to it and using Airplay by just saying "play x on Spotify," or is that even an option in the first place? and will it play on my Spotify account?