How resilient are the Cooperatively Validating Nodes (CVNs)

CVNs behave like any FairCoin node, they create the blocks and bundles them when signed and commits them to the chain. We can even say that CVNs are secretaries, who do not know each other. The consensus is created from the history, so it is clear which CVN is next. The one that creates the block is the furthest in the past. If a CVN is not online (grace period 60 seconds), it is skipped, and all nodes agree to try the next CVN. Each full node validates all messages. 70% of the CVNs need to sign. If fewer than this sign, then no blocks are generated, but non-functioning CVNs that have not answered to more than ten blocks are not taken into account in the 70% ratio.