Some Questions about "Style" in Graph Builder

[#1]

1)  When I use Style as Overlay encoding, how can I specify the "Theme" of the markers, e.g. to use hollow or markers?
[similar to the Graph Marker Theme setting in the Preferences]

dt = Open( "$SAMPLE_DATA/Big Class Families.jmp" );
Graph Builder(
	Size( 398, 333 ),
	Show Control Panel( 0 ),
	Graph Spacing( 4 ),
	Variables( X( :height ), Y( :weight ), Overlay( :age, Overlay Encoding( "Style" ) ) ),
	Elements( Points( X, Y, Legend( 17 ) ), Smoother( X, Y, Legend( 18 ) ) )
);