Brilliant, much appreciated kuba! I've done a little testing and it's working well.
Like you I'm also using Hue bulbs without a Hue Bridge, but also a bunch of other Zigbee and WiFi bulbs. They're all directly controlled by my local HA server, so this is a perfect solution that allows me to elegantly switch between regular automations and karaoke-mode when the Hyperion instance comes online.
Thanks!