TSimpleGraph and coordinates

[array81]

TSimpleGraph have the origin (0, 0) on top-left corner and the user can only create the chart on right and botton from origin (negative coordinate are not allow).
I'd like have 0,0 coordinate on the center of TSimpleGraph and allow user to move also on negative coordinates, so the user can move and create the chart in any directions.

Is it possible in any way?

PS. I think I have found a bug. If you set size line > 1 for link object the line is always draw as solid line also if you set dot line.