The position of the candidate label point still leaves quite a bit to be desired, especially in maps like this one where the polygons are anything but convex.
GEOT-2822 lays down ideas for a better labelling algorithm (which is, not surprising, not trivial to implement)
- goodness of fit: the polygon at the bottom and the polygon at top are too thin compared to the label so they don't get drawn. We should use a smaller default goodness of fit and make it programmable modifiable, which is something someone else also asked for
- the renderer does not try to place the label in a position other than the default label point. We could have it to move the label around