I would have expected that the result of a dash of 30,30 would be a series of equal sized dashs and spaces.
The result looks more like 30 dash, 15 space repeated.
        Line l3 = new Line(0, y, width, y);
        l3.setStroke(Color.BLACK);
        l3.setStrokeWidth(10);
        l3.getStrokeDashArray().setAll(30.0, 30.0);
unless I set:
        l3.strokeLineCapProperty().setValue(StrokeLineCap.BUTT);
in which case I do get equal spacing.

My expectation is that the should only affect the rendering of the end of the line and not the stroke pace in the middle.