(Mentioned on gitter, no responses yet.)
I saw 2d plots mentioned on this wiki page, but I understand that might be outdated/inaccurate.
Looking through what plot3d() does, I used Plot(ContourSeries(…)).show() as a workaround.
It seems like much of the infrastructure is in place to support a contour plotting function, would there be any difficulty doing so?
My guess is it wouldn't be too difficult to add it.