I am aware of one version of LambdaMOO that has partial unicode support, I have no idea how complex a partial integration of these types of features would be but having limited optional access to unicode character sets especially in terms of CKJ and diacritics for things like street signs, dialogue, SICADs and for sprinkling in certain types of descriptions would add a lot to the theme, both in terms of practicality but also flavor and aesthetics.