Creating an "Import Mix Template" macro.

Here's another version that you don't have to manually copy your file name. Simply hold CMD and press your button the first time you run the script and it will ask you to navigate to the .ptx file you'd like it to open. The script should then remember that path until you Re-define it by holding command and pressing the button again.

function navigateTo(path) {
    //Get a reference to the focused window in the frontmost app:
    var win = sf.ui.frontmostApp.focusedWindow;

    //Open the Go to... sheet
    sf.keyboard.type({ text: '/' });

    //Wait for the sheet to appear
    var sheet = win.sheets.first.elementWaitFor({ timeout: 500 }, 'Could not find "Go to" sheet in the Save/Open dialog').element;

    //It's a combo box on older OS'es, from 12.something it's a text field
    if (sheet.comboBoxes.first.exists) {
        sheet.comboBoxes.first.value.value = path;

        //Press OK
        sheet.buttons.whoseTitle.is('Go').first.elementClick({}, 'Could not click "Go"');
    }
    else {
        //Newer OS.
        //TextField with AXConfirm
        var textField = sheet.textFields.first;
        if (!textField.exists) throw `Can't find text field`;
        textField.value.value = path;

        sheet.elementRaise();

        textField.mouseClickElement({
            relativePosition: { x: 5, y: 5 },
        });

        sf.keyboard.press({ keys: 'return' });
    }

    //Wait for sheet to close
    win.sheets.first.elementWaitFor({ waitForNoElement: true, timeout: 2500 }, '"Go to" sheet didn\'t close in time');
}

function importSession(selectedPath) {
    const numberOfTriesClickingOpen = 40;
    const timeToWaitBetweenOpenAttempts = 200;

    sf.ui.proTools.appActivateMainWindow();

    // Open up Import Session Data
    sf.ui.proTools.menuClick({ menuPath: ['File', 'Import', 'Session Data...'] });

    // Wait for window to open
    var importWin = sf.ui.proTools.windows.whoseTitle.is('Open').first;

    // Navigate to folder
    navigateTo(selectedPath);

    sf.wait({
        intervalMs: 50,
    });

    // Click Open
    //Press Open, try up to 10 times
    var openSuccess = false;
    for (var i = 0; i < numberOfTriesClickingOpen; i++) {
        try {
            if (importWin.invalidate().buttons.whoseTitle.is('Open').first.elementClick({ onError: 'Continue' }).success) {
                openSuccess = true;
                break;
            }
        } catch (err) { }

        sf.wait({ intervalMs: timeToWaitBetweenOpenAttempts });
    }
    if (!openSuccess)
        throw "Could not click 'Open'";


    // Wait for import window to close
    importWin.elementWaitFor({ waitForNoElement: true });
}


function autoImportSessionData() {
    // Wait for Import Session Data window
    sf.ui.proTools.windows.whoseTitle.is("Import Session Data").first.elementWaitFor();

    sf.keyboard.press({
        keys: "cmd+a",
    });

    sf.ui.proTools.windows.whoseTitle.is("Import Session Data").first.buttons.whoseTitle.is("OK").first.elementClick();

}


function defineJson() {
    //save settings (goes in the script that saves the settings)
    let templateLocation = sf.interaction.selectFile({
        prompt: "Select your Mix Template",
    }).path;

    let settingsToSave = {
        templateLocation,
    };

    //this saves the settings file in the package directory of the command it is run from
    let jsonSavePath = sf.soundflow.thisPackage.getDirectory().path + '/savedSettings.json';


    let success = sf.file.writeJson({
        path: jsonSavePath,
        json: settingsToSave
    }).success;

    if (!success) throw `Error saving settings`

}

function main() {

    const modifierState = event.keyboardState
    const packageDirectoryPath = sf.soundflow.thisPackage.getDirectory().path;
    const jsonPath = `${packageDirectoryPath}/savedSettings.json`;

    if (modifierState.hasCommand || sf.file.directoryGetEntries({ path: packageDirectoryPath, searchPattern: 'savedSettings.json', isRecursive: true }) === undefined) {
        
        defineJson();
        log(`Template Chosen`);

    } else {

        let recallSettings = sf.file.readJson({
            path: jsonPath,
        }).json;

        let { templateLocation, } = recallSettings;

        importSession(templateLocation);
        autoImportSessionData();
    }

}

main();

FWIW @kitch I couldn't get the 'if no .json path stored, run the defineJson' we worked on in the webinar working. If you or @Ryan_DeRemer have a chance to poke at it I'd love to know what I got wrong.