Would it be possible to have a different StartButton image for use in Vertical Taskbars?

Having to use the same button image for both horizontal & vertical bars poses significant design limitations and the vertical bar is a very different animal from the horizontal bar. All the other images in the bars can be specifically designed for vertical vs. horizontal, the one exception being the Flashing Taskbar Button.

If it is technically feasible to designate a different StartButton image for vertical bars, that would be a very nice improvement in WB. A separate image for the Vertical Flashing Button wouldn't hurt, either.

Thanks.