Supporting mimic joints in URDF

[PawitKoch]

Is your feature request related to a problem? Please describe.
I am trying to import a Robotiq 2f-140 model via URDF importer into my Unity scene and it seems the mimic joint information that comes with the original file doesn't get implemented. This is confirmed when I exported the Unity model back into URDF from the robot model and found that the <mimic> tags were missing upon comparison between the 2 URDF files.

Describe the solution you'd like
A way for mimic joints to be implemented in URDF importer.

Describe alternatives you've considered
I considered manually setting other joints that mimic a specific target joint in my Unity script, but this obviously doesn't scale well to complex models with many joints.

Additional context
Attached are the 2 URDF files with one having mimic joint information missing.
robotiq_2f_140.urdf.txt (original URDF file)
robotiq_arg2f_140_model.urdf.txt (Exported robot-to-URDF file)

[PawitKoch]

Has there been any follow-up on this?