Would love to see any photos or hear of your luck with intarsia seeding. Especially with a scarf, since it's not reversible.
Last year I worked up a great scarf in merino that had seed stitches as a border (about 1 inch on all sides) and stockinette in the center--a little more work to keep track of what you are doing, but worth it. The knit border just doesn't do it for me.
If you are working in wool, you can always felt and block if you really like stockinette. Intarsia felted things are my new best friends!