The field EncodingSelected it is possible to enter a name of a codepage. For example enter utf-8 and UTF-8 will be used for that installation / installation group

Possible values can be found on the site below, use the Name column

Remember if there is no checkmark in the .NET framework support the underlying operating system need to have support for that encoding.

If no encoding is defined or the encoding is invalid, Encoding.Default will be used instead.