It would be very handy If you could select start and end elevation when doing analyses by elevation. Now C3D select the highest and lowest point from a surface. Sometimes you area only interested in a part of the elevations. If the interval is only 3 elevations, you can do this by hand, but if you need 10+ elevations, it could take some time. E.g. the surfaces go's from +5.0 till -34.0, but I only want an analyze between -3.0 and -18.0, each m.
Also handy would be that you can reverse the used colors. E.g. the colors go from light blue to dark blue, but actually you need from dark to light ... Saving the last color set would also be great! Now you always have to adjust the colors...
