Using RichText strikethrough <s></s> with TextTransparency above 0 doubles the transparency at the strikethrough line. This makes it harder to read and doesn’t give the desired effect. This also applies when using the <font transparency=0.1+></font and I’m not sure if this is intended.
In these examples, I’m using Font Source Sans Pro, Semi-Bold but this happens to all fonts and styles.
Visual Effect with TextTransparency
Before Utilizing TextTranspareny

After Utilizing TextTranspareny

Desired Effect Utilizing TextTransparency

Visual Effect with Font Transparency
Before Utilizing Font Transparency

After Utilizing Font Transparency

Desired Effect Utilizing Font Transparency

I’m unclear when the bug started, but I’ve found it today whilst working on a project of mine.