I just found MotionTrail3D creator original topic, it"s super interesting, they also talk about monetizing vs paid add-ons:
Supposing he would be interested and know enough C++ to do it, would it be possible to hire the creator of this add-on for a while so he can integrate it into blender as a core feature?
Older Motion Trail add-on
The thread above had a link that made me discover an older add-on called “Bart Crouch Motion Trail” that i think was free but i"m not sure it was updated for 2.82: