fid=sts.addFolder('newFolder')
sts.addMarker(39,-120,'newMarker',description='desc',color='#00FF00',symbol='fire',size=4,folderId=fid)
sts.addLine([[-120,39],[-120.1,39.1],[-120,39.1]],title='newLine',description='desc',width=8,opacity=0.6,pattern='M12 -7M0 5M9 0A3 3 0 1 0 6 0 A3 3 0 0 0 9 0,2,20,T;M0 0L12 0,15,20',folderId=fid)
Burping the folder checkbox does make the new features visible (and populates their icon rows in the left bar).