I found that trying to set a different width for the line attribute in a layer did NOT have any effect. The way I was using it caused lines to be drawn with width 1 every time.
If I recall correctly, there's also a bug with text attributes mentioned somewhere in the forums, but I haven't checked that one yet.
The file that needs to be patched is OpenGl_togl_begin_layer_mode.c:
(OpenCascade 6.3)
Line 112:
static float layerHeight = -1.;
-static float layerWidth = -1.;
static int layerPoints = 0;