Thanks for the feedback zulu85.
Yes, the alt-G is the one I avoid suggesting. Select two object and group them that way, the “average” position will be used. Since you are not into animation, that would not cause trouble.
Don’t get me wrong. I certainly love short cuts. I avoid them when I teach, as it takes too much out of the overall understanding. Only this one, and place object under or above, are the three I really avoid. Over the years I ahve run into many scenarios where those causing trouble. However, I’m pretty much alone with this ;o)
The core idea of anything in Cinema 4D is, that the world-origin is like a “Super Null” and provides the zero’d out version. Anything and everything relates to it, directly or indirectly. the main thing to understand is here the Global vs Local position (most visible in XPresso, though).
Not a single object is independent in its position or rotation, well, scale as well.
All of that leads to the procedure of: “Unparent” all objects, “Reset PSR” of the [former] parent and “Set-Parent”. The visible change in each of the child objects to former child objects, to child again object is visible in the coordinates. All of these coordinates, of each and every child under a parent must be adjusted. In this way.
Example, look at the coordinates when you do the “alt+G” shortcut, you zero out a single object that is now under the new Null. With two objects which are apart of each other, the result will be different.
I checked now everything that came to my mind, even the “Axis Center”.
My tip, to follow your idea of moving the axis faster, if you have no object on 0;0;0, then place there one. While in “Axis Modification Mode” enable as well Snapping with 3D and Axis snap enabled. This lets you very quickly move that axis to the Null as it snaps there.
Perhaps there is a hidden feature, but I’m not aware off. I tested Rick’s “Zero Out” script, I made a custom zero XPresso Tag, to set the values, but no luck. Perhaps the support knows it. Sorry.
All the best