docs not complete on Natural Neighbour 

There an not clear understanding on docs for https://github.com/sakov/nn-c/
This lib uses it own type for points, which works from qgis just with QgsPoint type and not with other like QgsMultiPoint. There no any description in docs on that case. 
https://saga-gis.sourceforge.io/saga_tool_doc/9.4.0/grid_gridding_3.html