In Admin portal, navigate to the desired edge band SKU. If the SKU is not owned, you will need to clone it before being able to make any changes. Once owned, select the Edit SKU icon against it.

In the window that opens, under the Properties tab, go to Product Dimensions and enter the new thickness value into the Thickness field.

Select Update Details to apply changes.

Go to the design in which the edge band is loaded and refresh SKU cache to load the changes.