Hey. The entire process is shown here. You do not need to mark anything for Zen Unwrap. It will do it itself if you are in EDGES mode. To stack only the selected parts, hide the ones you do not need. Currently, this is the only way to avoid stacking unwanted elements. https://cdn.discordapp.com/attachments/695620319741870150/1472955808932303043/StackingCubes.mp4?ex=6994747f&is=699322ff&hm=c10c03532eb993f3b921148ac63d22bcc7a0741a74397be68024f5c738b52c3f&