tmux.conf excerpt to toggle on/off session keybindings and prefix handling

toggle_keybindings.tmux.conf

bind -T root F12  \
  set prefix None \;\
  set key-table off \;\
  set status-style "fg=$color_status_text,bg=$color_window_off_status_bg" \;\
  set window-status-current-format "#[fg=$color_window_off_status_bg,bg=$color_window_off_status_current_bg]$separator_powerline_right#[default] #I:#W# #[fg=$color_window_off_status_current_bg,bg=$color_window_off_status_bg]$separator_powerline_right#[default]" \;\
  set window-status-current-style "fg=$color_dark,bold,bg=$color_window_off_status_current_bg" \;\
  if -F '#{pane_in_mode}' 'send-keys -X cancel' \;\
  refresh-client -S \;\

bind -T off F12 \
  set -u prefix \;\
  set -u key-table \;\
  set -u status-style \;\
  set -u window-status-current-style \;\
  set -u window-status-current-format \;\
  refresh-client -S
  
wg_is_keys_off="#[fg=$color_light,bg=$color_window_off_indicator]#([ $(tmux show-option -qv key-table) = 'off' ] && echo 'OFF')#[default]"

set -g status-right "$wg_is_keys_off #{sysstat_cpu} | #{sysstat_mem} | #{sysstat_loadavg} | $wg_user_host"

To send the get-out key (Ctrl+) to child T-Mux, just repeat it, and so on. So once the child T-Mux also enter the on key-table, now you have to press Ctrl+\ 4x to send it to the grand-child T-Mux.

This tricky requirement of exponentially-growing key presses to interact with nested tmux instances is solved in the tmux-matryoshka plugin (previously tmux-nested)