Time steps greater than 1 could only be tested after T15676 was fixed.
The contour is not visible because all segmentations tools are adding vertices at the default time step, which is 0.

New remote branch pushed: bug-15687-feedback-contour-for-4D-segmentations

All access functions to contour vertices had to be adapted within the tools. Also ContourUntils had to be extented for FillContourInSlice to specify the time step due to 2D slice .