The only applied graphics properties are the fill color, the stroke color and the rendering mode (which specifies whether the glyph is filled or/and stroked). Instead, Block and FixedContentEditor classes should apply all other graphics state properties (StrokeThickness, MiterLimit, StrokeDashOffset, StrokeDashArray, StrokeLineJoin, StrokeLineCap).

WORKAROUND: These properties may be applied after the text content is added. For instance, if you require changing the StrokeThickness of the text fragments which are stroked and not filled then you may use code similar to the one below:

foreach (RadFixedPage pages in document.Pages)
{
    foreach (TextFragment textContent in pages.Content.Where(c => c is TextFragment))
    {
        if (textContent.RenderingMode == RenderingMode.Stroke)
        {
            textContent.StrokeThickness = 0.3;
        }
    }
}