I briefly tried using LOOT using just the keyboard and found a some shortcomings:

• there's no visible change when you focus the menu bar, and you have to press the up or down arrow keys to then focus an entry before you can then navigate the menus
  • focusing the first menu entry by default when the menu bar is focused would solve this, if that's possible
• when selecting plugin cards, there's no indication which is selected, apart from seeing which card the context menu opens over when you open it
  • I think this just needs some styling applied in the delegate
• when you tab to the toolbar, you can change the current game, but you can't navigate to the other items (though you can get to them through the Game menu)
  • I'm not sure why this is the case, maybe it's because the other items are shared with the menus?
  • It's not that, but if I add QToolButton objects instead of QAction objects then the toolbar items can be tabbed through.
• when the sidebar is selected, its contents isn't navigable, all you can do is tab onward into the cards list, though if you click into the sidebar plugins list or the filters panel, you can navigate that, and from there tab into the cards list
  • I'm not sure why, the sidebar uses QToolBox, it might be worth contrasting that with QTabWidget, which is basically the same functionality with different UI
• when you've got the search dialog open, you can't then switch focus to the main window without dismissing the dialog, which clears the search result highlighting
  • it's probably worth moving the search dialog's inputs into the toolbar (or revealing another search toolbar) instead of opening a separate dialog for them
• the groups editor graph isn't usable using just the keyboard
  • addressing this probably isn't worth the effort, but it would probably be better handled by displaying lists of groups and their "after" groups, and inputs to modify them