3D CAD and model-based ideas are fostered by NIST (National Institute of Standards and Technology).
Let’s start with defining a “Neutral CAD File”. A neutral CAD file is a CAD format, generally governed by a commercial, government or international standard and is “open source”. Many can write it, and many can read it. It is not a CAD specific, proprietary format.
Now, also bear in mind, that a Neutral CAD File, is generally a derivative of the Native CAD format. Meaning it is a copy of the original file. Consider how that derivative file is used downstream in the product development lifecycle, and what relationship, if any, it has back to the originating source data.
This is where I make YOU work. Which is the master? Do you have a feedback loop to the source design data? Do you need to feedback to the source data?