This time I achieved a better fit by extending the front pattern pieces at the sides to the next size and adding the same amount of extra width to the sleeve at the front. The extra fullness in the sleeve was tapered to nothing at elbow level.
My inspiration for this fitting improvement was given by Sandra Betzina in one of her patterns for Vogue. I did not follow her tip exactly but achieved a similar result. You could call it a pauper's FBA or a lazy FBA (full bust adjustment). It adds extra width where needed - in the bust, waist and hip - but without the effort of altering the tissue that a conventional FBA involves. Sandra B's method also avoids adding extra fullness elsewhere (neck, shoulders, wrist) where it is not needed.