Instant Switch can only directly pair via Bluetooth with one iDevices product such as Switch, Socket, Outdoor Switch, Wall Switch, Dimmer Switch, or Wall Outlet.
For Wall Outlet, 1 Instant Switch can be paired to each outlet. For Wall Switch and Dimmer Switch, 2 Instant Switches can be paired in single-pole configurations and 1 Instant Switch can be paired in 3-way configurations.
Although you cannot pair Instant Switch to multiple products, there are a of couple options for adding advanced controls for multiple products:
Option 1: If you're using an iOS device and have an Apple Home Hub set up, the HomeKit platform allows you to create a trigger or automation to turn on multiple products. This way when you use Instant Switch to turn on the connected product, it will then trigger other products to turn on or off automatically. For more information, visit: Creating Triggers on iOS.
Option 2: You can also connect with the free service IFTTT. This would allow you to set up an Applet so that when the paired iDevices product is turned on or off, it can trigger another device to turn on or off. For more information, visit: Connecting iDevices Products to IFTTT.