According to @nic__carter, a chain split between incompatible node versions constitutes network downtime because exchanges and wallets must stop accepting or processing transactions to avoid double-spend risk (source: https://twitter.com/nic__carter/status/1992352769571999901). He states that transactions executed on the discarded fork are invalidated, meaning users who transacted on the poisoned chain experience effective downtime (source: https://twitter.com/nic__carter/status/1992352769571999901). He adds that a similar event occurred with Bitcoin’s 2013 28-block reorganization and that such an outcome today would be a major failure for BTC (source: https://twitter.com/nic__carter/status/1992352769571999901). For traders, this implies elevated settlement risk and potential exchange processing pauses during chain-split events, with higher confirmation requirements likely in practice per his assessment (source: https://twitter.com/nic__carter/status/1992352769571999901).