Can polyline objects be excluded from depth testing against terrain?

I would like to set depthTestAgainstTerrain true, but there are some graphics which I want to exclude from the test. In particular, sometimes I draw polylines and want them to participate in depth testing (so that terrain obscures them), but sometimes I want them to be excluded (so that they appear even through terrain).

I see that billboards and labels have a disableDepthTestDistance member that can be set to Infinity to exclude individual objects. Is it possible to get the same functionality for polyline objects?

Thanks,

Jacob