Thanks for your question.
Usually it's only the border layer that vendors want arcs, and could care less about arcs on any other layer.
All PCB manufacturing must deal with customer gerbers containing "dotted lines for arches" as I can assure this is something that has always been very common in PCB manufacturing. The reason they prefer arcs is because some NC routing machines will slow down around the arc areas because there are so many vertices that require processing compared to just one "circular move". The Gerber's you send are accurate however they're not optimized for routing efficiency that your manufacture would prefer.
During Export you can check the option "Detect Arc" and FAB 3000 will try to approximate them the same way that your supplier does. If arcs still do not appear in the Gerber files, than FAB 3000 was unable to approximate the arcs. Arcs in gerber files can cause problems for other tools (like viewers, dfm tools, etc.) and that's why the arc detection feature is turned off by default in FAB 3000.
Feel free to send me your gerber files sent to the manufacturer, and I'll be happy to review what we can do here to improve the arc detection during export.
Lastly, we also have a tool called "EasyGerb" which runs inside AutoCAD and can directly output arcs. You can create an entire panel in AutoCAD and then simply export to Gerber with arcs, etc. For more information about Easygerb view the following link. https://www.numericalinnovations.com/collections/easygerb