After letting the Tangled Yoke sweater relax overnight, and myself too, the fit had improved! I've given up trying to understand the whims of The Harsh Mistresses Gauge and Wool and just go with it. There's the usual yoke sweater excess at the underarm but not a big bubble like the first night. The fit is generally great, and I'll be able to steam out the few remaining bubbles under the cable.
I've been really sick so have no photos. Tomorrow I'm hoping to sew the steek* and insert the placket. I'll try to take photos of the process. I started trying to sew tonight with grey thread on blue tweed wool and it just wasn't working.
*Steek: A slit cut in a column of knitting to insert a sleeve or to create a cardigan opening. Lines of machine stitching can be sewn on either side of the slit to prevent raveling. I'm inserting a henley placket via this method.