It is finished!
I have thus far not managed to get the SuperFabric company to sell me their fine product, so the elbow patches, cuffs, and waist band are made from black aramid. In the event that I managed to secure some SuperFabric I will stitch the elbow patches closer to the edge in order to produce a flatter look. I stitched them on about 1/4" in from the edges and as a result they stand up more than I like. (I had intended to sew quilting lines around the circumference of the lower sleeve to promote rolling, as shown in the sketches, but I forgot. Perhaps I will do so once I replace the elbow patches.)
I wanted this jacket to feel just as natural with the cuffs flipped up as flipped down. To accomplish this the aramid cuffs are only attached to the polar fleece liner, leaving a tiny gap between the cuffs and the aramid outer sleeve. This worked as well as I had hoped and despite the stiffness of the aramid, the cuffs feel quite comfortable when flipped up.
In order to maximize the temperature range over which this jacket is comfortable, I decided to add some large zippered vents under the arms. This lead to a surprising aesthetic problem - while one side of the zipper was sandwiched between aramid outer and polarfleece liner, the other side was only sewed onto a single layer of polarfleece fabric. Either the interior or exterior would have to be unfinished. I experimented with leaving the zipper edge exposed to the outside, but made it look very finished by running a zigzag stitch along the edge. The black thread is invisible in the brown polarfleece and this keeps the zipper so flat to the cloth that it looks like a cosmetic black stripe. I'm really happy with that decision!