Midline colormap not updating for crossbar recipe

[RpfR2000]

I am trying to make a crossbar plot with just a midline (hiding the the notch. This doesn't work, by the way. One can set the color=:white as a workaround). However, there does not appear to be a midline colormap attribute, and the colormap attribute that does exist only updates the notch, not the midline. Is there a hidden attribute to get this to work?

[RpfR2000]

Just setting midlinecolor=colormap works