imo only the onSelectTab call doesn't have to be executed, but the setting of g_TabCategory and setting some sprites can be executed, when pressing esc before the init, the tabs will be hidden. So the check can move to old L75, this also allows not setting the function, if that is required somewhere

inline the hotkey stuff here (like the way it is done for the lobby button)

also the tooltip should be merged with the already existing tooltip: "Return to lobby."

If there were more collapsible elements, one might consider moving that to the tabs UI and possibly creating a custom hotkey to distinguish closing of the options dialog.
Just because we want to assign Escape by default doesn't imply that we have to use cancel (I guess that term is used a bit broadly as it also allows closing of pages after saving or this thing here which isnt cancelling anything either)
But should be good enough for now.