I would also be very interested. Likewise for the right sidebar. I'm on Mac, too, and actually use the system settings to define a few custom keyboard shortcuts. But that seems to work only for commands that are available from the menu bar – so for me, adding the toggles for expanding and collapsing both sidebars to the "View" item in the menu bar would already solve the issue.

Thanks!

This is implemented by Actions and Tags plugin and it works:https://github.com/windingwind/zotero-actions-tags/discussions/169

For Zotero 6, you can use Zutilo's functions:

> Like the functions above, the following two functions allow you to easily show or hide the collections pane (left pane) and the item pane (right pane). However, when the pane is shown, the thicker vertical divider ("splitter", "grippy", appears when the pane is hidden) remains visible until the width of the pane is adjusted.

> Item pane: Show / hide (sticky): Show or hide the item pane. When the pane is show, the thicker vertical divider remains visible until the width of the pane is adjusted.

> Collections pane: Show / hide (sticky): Show or hide the collections pane. When the pane is show, the thicker vertical divider remains visible until the width of the pane is adjusted.

https://github.com/wshanks/Zutilo/blob/master/docs/COMMANDS.md#navigating-the-ui-and-editing-items-via-keyboard-shortcuts