I recently got six(6) of the 2nd gen Amazon Echo Dots and placed them everywhere in my home. And I realized the policy of Spotify that is limiting to only one device to play music at the same time bothers me a lot when I set Spotify as a default music libary. For example, if one of my family members asks one of Echo Dots in his/her room to play music A, then music B on another Echo Dot I'm listening to stops playing.
I know there is Spotify Family Plan but my kids can't join that because they are just young and they don't have any email account yet. And also I don't want to create an account for them yet.
I believe Spotify could make possible to play the same music over multiple Echo Dots under the same network at the same time somehow even while it's not possible to play music on other multiple devices. Maybe by verifying some factors like if it's for Amazon Echo Dots under the same network under the same account.