Rather than define a new Name: http header for expressing the name of created resources, use the existing Content-Disposition header with a new disposition-type of "atom"
e.g. Content-Disposition: atom; filename=myfile.jpg
Content-Disposition is already commonly used for specifying filenames of downloaded files and attachments. Using the header in APP is a logical extension of these existing use cases.
Replace Section 5.2.6 Name: Header with the following:
5.2.6 Use of the Content-Disposition Header The POST to a Collection Resource MAY contain a Content-Disposition: header [RFC2183] with a disposition-type of "atom" that MAY be used to indicate the clients suggested properties for the resource. The server MAY ignore the Content-Disposition: header or modify the requested properties to suit local conventions. The Content-Disposition header is defined in [RFC3986].