Use dedicated buffer instead of pop up menu

[Noghpu]

Is there a way to move the menu into the corner similar to how which_key is drawing its menu with the helix layout, or a separate buffer in a split pane?

[Saghen]

No plans for this, although you, or someone else, could try implementing this. Take a look at how completion/list.lua interacts with completion/windows/menu.lua in completion/init.lua