For the Home Assistant users out there... Home Assistant now allows deep linking to tvOS.
The 2023.7 release of Home Assistant now allows you to send deep links directly to tvOS so you can now powerfully and easily control the Security Spy app on the Apple TV. Here is a demo of a dashboard I made on my Stream Deck to control my Apple TVs in my office with Security Spy:
I haven't been able to get the multiplex deep link to work on my AppleTV yet though, I'm not sure if it's an issue with HA or if it simply doesn't work with Security Spy on Apple TV, but I'm following the schema exactly and it just takes me to the main camera selection window.
But this is the biggest improvement to my use case for Security Spy since I first started using it over a decade ago.