Today, the Commerce CMS supports searching for an image via its filename. So a user can call the query endpoint with a filename and extension and receive the asset in response, if it exists. This works in conjunction with the image re-sizer service.
There has been a request to enable a similar search pattern for file binaries that are not served through the image re-sizer. This feature, if implemented, would allow you to call the CMS query endpoint with a filename.extension to retrieve the file binary as a response.
Please take a moment to review this ask and vote for it if this is important to your business.