in the case of resource-bar-heavy.(WindowSimpleShared).xdb, you need to change the content; I think simply BackgroundSimpleScallingTexture won't be enough. Could you take a look when you have some free time?

If you are upscaling the resource bar, in resource-bar-heavy.(WindowSimpleShared).xdb, add Scalling to ...back.(BackgroundSimpleTexture).xdb#xpointer(/BackgroundSimpleTexture), so it becomes ...back.(BackgroundSimpleScallingTexture).xdb#xpointer(/BackgroundSimpleScallingTexture), and replace the back.(BackgroundSimpleTexture).xdb file with back.(BackgroundSimpleScallingTexture).xdb, as shown in comment #26. Specify the path to the texture in it, just like in the replaced one, and set the size to 1394x104 (if the texture itself became 2048x128 after upscaling).
If something doesn't work out, just send me the finished texture, and I'll take a look.