I just want to update this post. I get reply from our developer, we can set the offset for the scenario like yours (Circle outer, Start inner).
Please view the test code:
PointStyle pointStyle = PointStyles.CreateCompoundPointStyle(PointSymbolType.Circle, GeoColors.White, GeoColors.Red, 1, 24, PointSymbolType.Star, GeoColors.Red, GeoColors.Black, 1, 18);
pointStyle.XOffsetInPixel = -1;
pointStyle.YOffsetInPixel = -2;
valueStyle.ValueItems.Add(new ValueItem("1", pointStyle));
And it looks like:
Wish that's helpful.