The new feature for the lines is very helpful.
Looking at consistent marker control in Graph Builder , the new feature is exactly proposed mode:

Very helpful will be the mode:

e.g. to generate the first graph with hollow markers and the second graph with filled markers.
or to use the left axis for hollow markers and the right axis for filled markers.
I just tried Type Properties( 0, "Marker", {Marker( "Hollow" )} ):
Names Default to Here(1);
dt = Open( "$SAMPLE_DATA/Big Class Families.jmp" );
Graph Builder(
Variables( X( :name ), Y( :weight ), Color( :age) ),
Elements( Points( X, Y, Legend( 1 ) ) ),
SendToReport(
Dispatch( {}, "400", ScaleBox,
{Legend Model(
1,
Type Properties( 0, "Marker", {Marker( "Hollow" )} )
)}
)
)
);
... which doesn't produce the expected result (a graph with hollow markers) - but provides another cool option *)

*) cool really ?!??! Why?
Just save the code of the generated graph and find: Marker( "" ) . It can be used to hide a markers very easily/efficiently.
Type Properties( 0, "Marker", {Marker( "" )} )
can be used to hide all markers (almost too extreme: the user doesn't have any chance to change the marker / show them ).
let's search for interesting use cases ...