Hi,
I noticed the following behavior.
I created two shapefiles for this test : line.shp and surface.shp
Both contain several feature including one with multiparts (multiline and multisurface).
When using CoordinateExtractor with mode Specify Coordinate + index=0, I get in the _x and _y attributes the first point of the first part of line/surface.
I assumed I would get the same with @XValue() and @YValue() but it is not the case for the multiparts features.
For those I get a point far far away from the feature, with integer values for X and Y.
Anybody knows why ? Is it a normal behavior ?
Tested on FME 2018.1 and 2019.0, see enclosed test workspace on FME 2019.