Win 10 Pro 2 X Asus Rog II
Short description of error
Constraint won't follow proxied armature's bone correctly in any given space.
Exact steps for others to reproduce the error
A portion of my project directory is in this archive:
Just open the scene file "SHOT_06_RV01_01.blend" in the "Scenes" folder of the project directory and check out the empty named "CAM TARGET" which has a 'Copy Transforms' constraint applied to it and is constrained to the bone named "Forward" in the rig armature of the plane which is linked from the "Source_Blends" folder. It should stick to the bone's center in world space, instead it is dubiously offset some amount.
Been working on this in 2.79a RC, due to the fact that 2.79 is just too buggy to do any serious work on (randomly and persistently crashes like crazy when you interact with the armature)