Lots of confusion… maybe this will help:
SACD - Super Audio CD is a proprietary optical disc format jointly created by Philips and Sony. The disc is the same physical dimensions of a CD but contain a 4.7GB layer (HD). The focal length of the HD laser is narrower than the CD laser in a SACD player. This allows for the disc structure to hold both the HD layer as well as a standard Redbook CD layer. This makes the discs backwards compatible with all CD players (as long as the disc contains the CD layer). The HD layer contains DSD encoded audio.
DSD - Direct Stream Digital is a 1-bit encoding of audio
DVD-ROM - A disc same physical size as a CD and can hold 4.7GB of data per side. It is single layer but can be double sided.
DVD-R/RW/RAM etc. - These are DVD discs where the layer which holds the data can be written by consumers. Depending on the disc this can be done once or multiple times. They have same capacity as DVD-ROM at 4.7GB per side.
All Marantz is saying (from your description) is that the SACD player can read DVD-Rs. If you were to copy over a bunch of DSD files to a blank DVD-R (on a computer) and then insert it into the player the player would recognize the files on the DVD and you’d be able to play them. They are still full rate DSD and contain the same bitstream as what would be on a SACD but the disc itself is not a SACD.
Hope that helps.
Personally, this sounds like a ton of unnecessary work. Get a network transport and be done with it Just feed the files over the network.