You are missing the point !
I do not want to open another CAD package just to represent a curve accurately
SU, Apart from being an exceptional 3D software is also great for
2D work as it is also exceptionally easy to draft, quick, intuitive, flexible, easy to manage
EXCEPT FOR CURVES
I cannot represent curves accurately !
If I could do that I could ditch Autocad [aka Draftsight ] entirely.
I am not expecting to represent 3d curves, just 2d curves mathematically correct.
All my orthogonal lines are mm accurate, but when I draw a curve it is immediately compromised
The world needs a simple intuitive 2D software package and SU is almost there
An no LAYOUT is not it!
LAYOUT does not know what is is and suffers accordingly!
Have you never exported or imported a curved line to or from a DWG ?