Hi @Nico ,
Thank you for your question, this definitely started a conversation in the committee to see how we can improve the rules for 2024 
Is the use of several Lego Bricks within a single robot allowed?*
Yes, having more than one “brain” it’s allowed. This can be a combination of bricks (like 2 LEGO bricks), with multiple brands or types (1 brick with 1 arduino).
which modes of communication between bricks are legitimate?
1. Wired connections
You’re correct, all wired connections within a robot are allowed. All the wires required to connect the “brains” are considered part of the robot.
2. Wireless connections
The intention of that rule was to simplify other competitions where they require multiple robots, like RCJ Soccer and RCJ OnStage. In the scenario of RCJ Rescue, it is there to provide a valid wireless way of communication with other teams during the super team competitions.
Now, considering the ambiguity of the rules and after discussing this with the committee members, we determined that for now we will be accepting wireless communication between the same robot components with the previously mentioned protocols. We recommend teams to do not opt for this option as we cannot guarantee that the wireless communications will work great in the competition arena and/or there will be a “safe” connection guarantee for these protocols (for example, a malicious spectator trying to connect to unsafe bluetooth ports to cause performance issues in the robot). We will be working into making better changes in the 2024 rules for this case.
Thank you!
Diego Garza Rodriguez
2023 Committee