Currently the NumericRasterizer seems to always work with 'Last Wins' mode. That is, the transformer uses z-coordinate of the finally coming vertex as each cell value, if two or more input vertices are within the same cell.
It would be nice if the transformer could work with several modes such as Min, Max, Average, First Wins, Last Wins, Standard Deviation, etc. This might be useful especially to analyze a point cloud efficiently, in conjunction with some point cloud transformers.