The region I'm worried about is the small black line between the white region and the gradient region on both sides, outlined in red here. I'm concerned that the machine will interpret that as the intended exposure at the location, resulting in a strangely formed photoresist structure.

Would I be able to make the polylines invisible or infinitely thin while exporting to bmp? It's the only format this application accepts, and I'm concerned about intermediate exports disrupting the scale of the drawing.

Thanks

Edit: Forgot to include the bmp file