Meh, I've had had clusters with close to 1k nodes (w/ cilium as CNI) and didnt have major issues
One of the main issues of cilium is that the bpf maps scale with the number of nodes/pods in the cluster, so you get exponential memory growth as you add more nodes with the cilium agent on them. https://docs.cilium.io/en/stable/operations/performance/scal...