Do I have to prevent nodes created from the same connection gene to have different IDs/innovation number? In this example, the node 6 is created from the connection going from node 3 to node 4:
In the case where that specific node was already globally created, is it useful to give it the same ID for crossover? Because the goal of NEAT is to do meaningful crossover by doing historical marking. The paper from Kenneth O. Stanley says at page 108:
[...] by keeping a list of the innovations that occurred in the current generation, it is possible to ensure that when the same structure arises more than once through independent mutations in the same generation, each identical mutation is assigned the same innovation number.
Why don't we do that for node genes too?