It's actually a 13W3 monitor cable, used in high-end computer workstations, predominantly in the '90s. Particularly common in Sun workstations. Yes, however the P3 tops out at 48KHz, and the D2D-1 will output at 96KHz if you want. Of course, it does have a 48KHz mode for the P3. My SFT-1 does not have a 13W3 "I2S-e" output. At the time you could send your SFT-1 into the factory to have the output added, cost was around $800 if I recall correctly. All Sonic Frontiers "Transport 3" transports do have the output.
The D2D-1 is pretty neat. I actually really like what it does with all of my DACs. Plenty of debate on whether or not what it does is a Good Thing, but with the SFD-2 Mk.III especially, it seems to add a noticeable amount of depth and palpable-ness to the presentation. Compared to using it in transparent jitter-reduction-only mode, in 24/96 upsampling mode, it seems that each instrument is more clearly defined in its own space and allowed to pop out of a super black background...........