yoseph1998:
then any extra strip wanting to pick an empty channel can just walk through the channels till it finds one without traffic.
I'm not sure that you mean by "extra strip" but there is no need for every master-slave group to use a different channel. Different addresses will probably be sufficient unless there is a very high update rate.
I built 4 pairs of controllers for a model railway system and they all work quite happily on the same channel using different addresses for each pair. Each pair sends messages about 10 times per second. The system is designed to withstand occasional data collisions.
However, based on my current knowledge of nRF24s if I was building the system now I would just use one master to poll the 4 hand controllers. and that would avoid the collisions.
...R