How can I update meta title/descriptions in bulk using this extension?

This can be achieved by using the “Update Attributes” action. Choose it on the product grid and then modify meta data or any other attribute as you need:

How can I change the meta title in Magento 2?

To change the meta title in Magento 2, follow these steps:

1. Login to your Magento 2 admin panel.
2. Go to Content > Configuration.
3. Select the desired store view from the configuration scope.
4. Expand the HTML Head section.
5. Modify the value in the "Default Title" field to change the meta title for the entire store.
6. Save the configuration. The meta title for your Magento 2 store will be updated accordingly.