Denon AVR-X3200W - How to block Spotify?

[chasethelasers]

Does anyone know how to block Spotify on the AVR-X3200W? It's causing me a massive headache.

If a friend attaches to my wifi, they can send a stream to the amp. That's great - but when they leave, and even travel to another country, they can still control the amp as there is no authentication with Spotify Connect. By design, it allows the last person to control the amp irrespective of the network they are on.

The answer in other forum threads is to open the app and steam to it - which will kick the last user off so they lose control. Fantastic - but they fail to mention you can only stream to devices with Spotify premium.

They only choice I can see at the moment is to either:

1) Disconnect the amp from the network entirely - Not really an option as I lose too many other features

2) Pay Spotify a monthly sub, so I can kick people off Spotify Connect with an app on my phone.

There doesn't appear to be a way to disable this feature. The best I can do is to disable the network when in standby, which will stop me from being woken up by friends accidently selecting my amp (or if it was the last used device). 

I've not looked at port blocking yet, as Denon / Spotify provide no port information from a quick Google search, but if it's uPnP based, then it'll probably try to use a different port anyway. While I'm comfortable with firewall rules, I can't run a whitelist for a home network, as I'd need to add an infinite amount of stuff to it.

The only 100% way I've found to kick people off my reciever is to factory reset it. This is unacceptable.

Does anyone have any suggestions? I do not need a subscription at this time.

Thank you.