Not true. Or rather: in theory what you are saying would be true, however in case of Slack it simply doesn't work: Slack handles unreliable transport worse than IRC - IRC never dropped or duplicated messages; you could reconnect to IRC client under a tmux session from anywhere and it would do the right thing.

> you could reconnect to IRC client under a tmux session from anywhere

That would actually be a pretty decent solution if it could be automated on a mobile device: run the IRC client in the cloud and then have tmux auto-reestablish every time it gets its connection dropped while the mobile device moves around.

I'd have to see it in action to be confident that a continuously-dropping-and-reestablishing tmux won't drop incoming messages or double-send though.

People (like me) have been doing this for over two decades now. It's quite well tested :-)

Excellent! Do you have a link to a write-up on how to set it up?