Quiet some time ago i made an interface to test how windows use the windowpieces files, having found it again recently while cleaning out my pc i thought someone might like to use it.
Called DigitalICE it is a base graphics modification, the only XML file that is altered is equi_animations.xml to resize a couple of window borders and the different mouse cursor.
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It should work with any pure XML modification, such as bag mods inventory mods etc as long as they leave the animations file alone. It does come with some modified XML files, but these are purely cosmetic and not core files. (can you really miss the window selector?)