After testing a number of different lace patterns, I decided to use a plain stocking knit stitch for the top portion of the sweater and the main part of the sleeves. The rationale for this design change was that using two different lace patterns involved more complex changes in terms of math and shaping and that the stockingknit stitch offset the beauty of the fishtail lace.
To offset the top portion of the sweater, I reduced the number of stitches to make it more fitted and used 4 rows of garter stitch instead of a ribbon used in the model. I shaped the armholes to accommodate a set-in sleeve which I like.
For the sleeves, I knitted 3 repeats of the fishtail lace to have a frilly cuff. Then I reduced the number of stitches and used 4 rows of garter stitch to set off the lace.