Pixieset offers the ability to select multiple Collections at once - allowing you to quickly apply bulk changes to different Collection Settings including Design, Favorite, and Store Settings. You can do this from the Collections page in your dashboard.
Using the Bulk Edit Feature:
You will see a ‘checkmark’ icon when hovering over Collection thumbnails. Click the checkmarks as needed to select any Collections you wish to edit, and click Bulk Edit. From there, you will see the available bulk editing options in the popup: