When setting the "Collapsible Headings" extension settings through the jupyter_nbextensions_configurator dashboard, then trying to set the "Command-mode shortcut to uncollapse (expand) the selected heading cell" will not work, but will wrongly set the entered shortcut to the "Command-mode shortcut to collapse the selected heading cell" setting (just above).
When setting the "Collapsible Headings" extension settings through the
jupyter_nbextensions_configuratordashboard, then trying to set the "Command-mode shortcut to uncollapse (expand) the selected heading cell" will not work, but will wrongly set the entered shortcut to the "Command-mode shortcut to collapse the selected heading cell" setting (just above).