In your network setup, if you want the controller to send a message to all devices for initialization without using a loop to iterate through all possible node IDs, you can consider utilizing the broadcast functionality of your communication protocol.
Typically, most communication protocols, including MySensors, support broadcast messages that can be sent to all devices within the network. Broadcasting a message allows you to send a single message that will be received by all devices simultaneously, without the need for individual addressing.
Consult the documentation or API reference of your specific communication protocol (e.g., MySensors) OR refer this [spam link removed by moderator] to understand how to implement broadcasting functionality within your network.
Hope it helps you.