How to disable iTerm2 tmux integration

iTerm2 runs slowly when using tmux (without -CC control mode integration). It is clearly designed with the intention of using -CC. However, I don't like the desktop window management of tmux windows/panes. I want tmux keyboard shortcuts and everything in a single iTerm2 window. Is there a way to disable tmux integration in iTerm2 so that I can tmux without using -CC? And so that it won't lag? If you are having difficulty trying to reproduce, try opening 2 tabs attached to the same tmux session. Compare it's I/O performance to the system terminal attached to the same tmux session.