Expand Subitems in Multi-level List Boards

We would like a way to set the default for multi-level list boards so subitems are all expanded or all collapsed when opening the board.

On regular boards that do NOT allow multi-level subitems, I believe you can use control i to expand all subitems and set that as the default when opening that board. However, for multi-level item boards, you have to manually click each grouping to expand subitems, which gets cumbersome when you're using the boards frequently.