ideally the VTK widget should do the “right” things and log warnings if needed
porting change from ctkVTKAbstractView directly into VTK. As mentioned by @lassoan , we may do that in the future.
VTK version could be updated in Slicer automatically every other days so that issues related to Slicer’s use of VTK could be detected promptly
volume rendering test in VTK could be improved to better capture Slicer use cases
automatic conversion of segmentation to label map for selecting inputs to CLI modules. This is not yet implemented but should be only a few small changes - @ihnorton see updated notes in issue #4400 for details about what would need to be changed