A pure and true silk coated yorkie will not have curl or a wave to their coat. My Radar, my Tucker who are champions and then I have Krissy all have "straight" hair no wave or curl. Harvey probably has a modified silk and may have a wave to it but no curls. Then I have brookie and Murphy who are cotton coated and of course they have curls to their coats.
When you have a pure and true silk coat you will not have wave or curl to it. I would welcome anyone at a show to see Radar after his blow dry with no iron to it. I will be in NY in Feb and I have no issue with anyone watching me bathe and groom him