There is no concept of choosing encoding at compile time. Encoding is always decided when the conversion occurs.
I de-compiled the class and the special chars, that are used in property values, show up as '\uFFFD'
You are probably looking at a constant that was stored as 16 bit unicode.
Thus at run time they get rendered as a '?'
The \uFFFD character is a place holder for those characters that cannot be converted correctly.