On a side note, if you want to create a design for reload on another product, you can create a new product in WooCommerce, then set the Design ID of the design you want to load on it in the Advanced options section in the MyStyle Tab, beneath where you enter the mystyle Custom Product ID.
If you do this, that new product will always load that saved design, no matter what product template you set it to load.
When you use a design from a different product, the sizes and aspect ratios will often be different. When the design is loaded on any other product template, the MyStyle app will do it’s best to transpose the design proportionally onto the new product, moving things around so that it fits the new size as best as possible.
The transpose process is not perfect, but works pretty well. It really just depends how different and how far off the product template is from the one used when creating the design. If they’re both wide rectangles, for example, it will work great. If one is a tall rectangle, and the other is a wide rectangle, for example, it will have a harder time shifting the objects around proportionally, but will still try it’s best to do so.