I have experienced symptoms far worse than netsplit on Slack on at least four occasions in two and a half years of usage for work, with messages getting lost, duplicated and reordered, differently in different clients, and generally with no obvious indication that things are broken, unlike with netsplit where you’d see a bunch of parts/quits signalling the problem. Eventually it decides on what I hope is a consistent history, but even that only works because the clients are slaves to the server and don’t cache things.