How many line segments in a wavy polyline are too many before one blows up their cnc machine?

I'm trying to draw a wavy line about 15" long. It can't be faceted at all. Very organic looking.

So, I have two questions:
1-It's easiest for me to draw the shape I want with the spline tool. Do I need to convert this line to a polyline when I send the dwg file to the cnc? (The CNC runs on Millwright 6.)
2-When drawing a 15" wavy spline I can convert it to a polyline and then specify the precision from 0-99. Roughly what number along that range would remove faceting, but not bog down the program?

It would be a lot easier to test this out on my own if the shop wasn't 30 minutes away. So unfortunately I can't walk over to the machine and run a test cut.

I'm running autocad for mac 2015.

Here's where it's asking me about the precision:
Attachment 261482

Would adjusting anything in window #2 (below) improve how smooth the line is cut?
Attachment 261480

I'll be glad to hear about the easiest way to accomplish this task.

Thanks,
Lee