Tab icons still are not adjustable

I really appreciate being able to adjust the tab sizes in V6. However, there is still inconsistency with the tab images. For example, look at the layer icon from the pane tab and the toolbar tab:

image

There is an apparent method to adjust these images, but it looks like it’s not “hooked up” behind the scenes:

Is this really not intended to work, or is it an oversight?

Thanks,

Dan