Even though I put DH's sweater aside temporarily, it has not been out of my thoughts. I had four hurdles and I've solved a few of those. The first was the design of the front openings. I needed to create something that would fill the space of the middle Saxon Braid that is on the sweater back. After much trial and error, I came up with this S-cable:

This swatch is intended to show how the front will look around the buttonbands, and I just used 5 stitches of K1, P1 ribbing to represent this. The color of the swatch is closer to the color of the yarn. It was cloudy today, and most of my photos looked gray.
I had hoped that this cable would mirror the shape of the Saxon Braids on the front, and it does:

I will position the pockets so that they fall at the point where the first S-cable indents to the button band.
I'm not quite sure where the V for the shawl collar will start. It has to be either at the orange marker or at the aqua marker, and I'm thinking that the higher V will be warmer. I also haven't yet worked out the exact number of decreases for the shawl collar, but it will be knit with the front and not attached afterward.
But tonight I can cast on for one front, and I can get up to the armhole before I have to solve another big problem. So the two hurdles that remain are where exactly to place the V and the shaping for the collar.
I'm not sure if the buttonholes should be vertical or horizontal. Any thoughts?