AT
A nice 12-24 DSD track recorder/playback machine going through analog hardware would be nice - use it like a reel to reel. If you could do some editing, like switching between takes, would be even better in SONAR. Best of both worlds. Is there any reason you couldn't "splice" DSD tracks in software w/o going pcm?
At the moment the issue would be processing those tracks. In general, I don't know if there are many, if any, algorithms for operating on PDM sound. All the (very few) DSD systems I've heard of use what they call "DSD wide" which takes DSD but converts it to 8-bit PCM at the DSD frequency or use "DXD" which is just high sample rate PCM. Either way it is an effective conversion from PDM to PCM. Specifically, all the FX and synthesizers you currently have work in PCM, so the data would have to be converted to be sent to them, and then converted back.
As a practical matter, it isn't likely to be much more than a curiosity and playing for engineers and audiophiles. Goes double since compressed formats are the thing these days. Broadcast, cinema, streaming, etc all use compression and all those compression algorithms need PCM input because of the way they deal with sound.