Ah, but I suspect it still is: not the tmux config option indeed, but the vim config option. After all, I think with that `tmux send-keys`, you're sending input

Ah, but I suspect it still is: not the tmux config option indeed, but the vim config option. After all, I think with that `tmux send-keys`, you're sending input to vim, aren't you? And vim itself does escape sequence interpretation.