Sequoia Popup Menu Challenges

@Tristan,

Here's how I would do it.

The popupMenuSelectAndWait function waits for the popup menu to close before moving on.

/**
 * @param {Object} args
 * @param {AxElement} args.popupButton
 * @param {String[]} args.menuPath
 */
function popupMenuSelectAndWait({ popupButton, menuPath }) {
    // Wait for the Popup Button
    popupButton.elementWaitFor();

    // Click the Popu Putton to display and get the Popup Menu
    const popupMenu = popupButton.popupMenuOpenFromElement({
        anchor: "TopLeft", // Required to account for possible menu panel overlaps.
        relativePosition: { x: 5, y: 5 }, // Required to make sure the menu is not being picked from the Popup Button's frame boundaries.
    }).popupMenu;

    // Select the Menu Path
    popupMenu.menuClickPopupMenu({ menuPath }, () => {
        sf.ui.frontmostApp.appActivateMainWindow(); // If the menu selection fails, activate the app's main window before throwing an error.
        throw `Failed selecting menu path: ${JSON.stringify(menuPath)}`;
    });

    // Wait for the Popup Menu to no-longer have children in turn confirming that the menu has closed.
    sf.waitFor({
        callback: () => !popupMenu.invalidate().children.first.exists,
        timeout: 2000,
    });
}


const outputPath = ["physical output", "Mac Studio Speakers 1-2 (Stereo)"];

sf.ui.proTools.appActivateMainWindow();

const bounceDlg = sf.ui.proTools.windows.whoseTitle.is("Bounce Mix").first;


//Set "Mix Source" - Popup Menu
if (bounceDlg.popupButtons.allItems[1].value.invalidate().value !== outputPath[outputPath.length - 1]) {

    popupMenuSelectAndWait({
        popupButton: bounceDlg.popupButtons.allItems[1],
        menuPath: outputPath
    });
}