The method I suggested allows you to change the default origin of any or all transforms, except scale of course. You won’t see the change until you drag another instance of the same mesh (actor) into the view port, after confirming changes. Essentially, it changes the mesh’s alignment relative to the red, green, and blue arrows in your picture above.
If you need data about how far your actor is from its origin, could you not just add a small, invisible scene component to your actor, which always remains true (true in the navigation sense)? And, just perform calculations (dot product) between their forward vectors or something?
Lastly, you might find that someone has already tackled these issues in tutorials: