We noticed that when you convert a LandXML in the PC Version it identifies the Linework defined in the Source Data Section of the LandXML and allows you to select it as Linework (they call it Background Linework but it should say Design Linework), however the Web Version of File Flipper only creates a Surface from the data and doesnt allow you to pass the linework to an SVL or DSZ file.
This has been reported