Hi Aaron
Not sure if there is an existing adapter module for this.
My two cents would be to have a Java mapping after the graphical mapping (cos I'm more familiar with Java than XSLT)
Here's the approach for the Java mapping:
i) Convert input Stream to a String
ii) Use replaceAll() method of String to replace all occurrences of the escape sequence to normal XML format, i.e. > to >, < to <, etc
iii) Convert modified String to output Stream
There are only a handful of special characters, so logic shouldn't be too complex.
Rgds
Eng Swee