Hi Edmund, I might not be following what you are saying, but my thought is the 3 foveon channels could be stored in a similar fashion that Pentax does. The DNG for the x3f file could still need special handling, but why has Sigma been so quiet about their raw spec, they mishandled the raw data from the Quattro when it came out, and they still have some areas that need improvement, innovation on SPP has ground to a halt recently.
I am actually interested to know how short a time Pentax's 4 shots need, and what kind of artifacts are generated in moving objects. Unfortunately the imaging resource review lacks these basic details, and at present no manual is available to download.
I was able to rent the OMDEM5II and use it in the field, I was not really able to make good use of the HR mode simply because things in compositions tended to move more than expected, even with something of a 1/200th of a second, the artifacts rob the resolution quite a bit in foliage and branches. Even wind buffeting the tripod was problematic at times, or required extra waiting intervals for longer wind lulls. Substituting in lower resolution components, there is a mismatch in detail transitions and noise.