You could explode the hatch in Rhino before exporting. This will convert them to regular curves.
On the note of the hatch - check this thread and the excellent plugin by @SamPage:
The insulation hatch that I made with this tool and that I posted here I didn’t have to change the global hatch scaling for it to fit in your file.
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Not sure if I am understanding you correctly but perhaps setting the Ypadding to a very big number when creating a pattern will achieve what you are looking for?