I have read some old posts (2013) about support for PolylineM/PolylineZM being a potential enhancement. I don’t see any other reference to these types. Is there any level of support for these types yet?
Our developer ever did some research about this problem. But the result is we found we don’t have so strong scenario to support this type, and this type should be used by the future 3D map.
If that’s important for you please let us know your scenario, so our developer can research that and see whether we will reset the feature priority.