Tbh that doesn't sound like a particularly troublesome task. Super-set the language with some new accents, symbols, and new punctuation markers and then off you go.
I read the parent post as suggesting that the appropriate "acting" cues and emphasis might be explicitly annotated in the text just as the intonation and punctuation in normal text.
However, I'd guess that it's simply quicker and more efficient for someone to just properly act and speak the lines with a dramatic effect and any explicit annotation of how exactly they should be said takes much more time and effort.