sshing into a server only happens within one shell. Thus you can open tmux there and that's the only level of granularity you can have.

iterm window->iterm tab->ssh->tmux windows->tmux panes

With `tmux -CC` it lets you hoist that chain upwards and map the entire ssh session into an iterm window.

iterm window (ssh session) -> iterm tabs (tmux windows)

The biggest benefit for me is that you can then open another tmux session within the CC one and use tmux as normal

iterm window (ssh session) -> iterm tabs (tmux windows) -> tmux2 windows -> tmux2 panes

And then the normal feature of tmux is that it persists across ssh sessions. This also means that the entire iTerm2 window and all its tabs and splits are also maintained across sessions. I think my current layout on my main development machine that I remote into is over 3 months old.

Another point of view is that it decouples the state of your tmux tabs/panes from your terminal emulator itself. e.g. if you use this locally instead you could then terminate the entire iterm program and reopen it and restore the same exact window/tab/pane splits you previously had. This is a nice perk for restarting/updating iTerm.

First, some background: Tmux is great but (like GNU Screen) introduces a layer of abstraction between you and the shell. You have to use its special keybindings to create new windows, switch window/pane, or most annoyingly to scroll through history.

Control Mode removes that layer of abstraction, so (with iTerm) you can use all the normal terminal emulator functions to do what you expect: click on panes to select them, tmux windows are just native tabs, and you can scroll the terminal natively

In effect, all the UI compromises you had to do to make use of tmux... go away.

It’s a huge benefit, because it means all the friction of using tmux disappears. Instead of thinking “do i really want to deal with tmux’s UX for this quick ssh session?” (it’s never as quick as you think) I just do it. All my terminal sessions are now in tmux. If I’m doing something on a remote machine, i can confidently close my laptop and know i can restore later.

the iterm mode allows one to create, split, resize remote terminals as of they were native terminal windows, instead of all of them being contained within one terminal window and controlled using completely different keyboard-only shortcuts (via tmux)