Select Builder and you can find "Open Auto Build As Default" which will make any product you desire to only give customers the option to auto build

If you turn this feature on be sure to "Save All"

Click "Edit" for the product you wish to turn "Open Auto Build As Default" on

Select "Open Auto Build As Default" "ON" within the product

Then check out your "Open Auto Build As Default" for yourself

After selecting the Build a Gang Sheet Button the customer will be view Auto Build and able to add as many designs they want.

Auto Build - Upload Multiple Images At Once
With Artboard Margin
in
With Image Margin
in
No Images uploaded, Please upload your images or select from the gallery.
Upload Image(s)
From My Images
From Gallery

Once there done designing they can select "Apply"

See all the gang sheets their designs fit

They can check out or edit any gang sheet they want

Builder Settings: Open Auto Build As Default