So I did it — I reknit the sleeve a fourth time. Actually, to be fair, after two reknits, I knit a second sleeve, compared it with the first sleeve, and decided to reknit that first sleeve for a third time. But somewhere in there, there are four sleeves.
I decided that the sleeve would look more balanced with just a bit more of the darker color/lace section and less of the lighter color. For reference, the lighter one is Sundara superwash sport merino (sadly no longer available) in Cantaloupe; the darker one is YoYo superwash merino in La Nouba.
I'm really pleased with the sleeves now and I think I'll seam them in before I knit the "skirt" of the coat. Then it's on to the neck/"buttonband" edging — which will be applied I-cord.
Meanwhile, Trellis is done except for buttons and labels!
It's incredibly soft and cushy.
* — in his sleevies!