Long answer: Because it’s not made for it. It’d probably make less power.
A exhaust chamber has what’s called a “tuned length “. There are many factors in determining that. Now which order that will make the most sense
Tuned length is determined by desired peak RPM. That would actually be almost the same for any engine. However the size/volume would be totally wrong. That starts at the port area at the cylinder. Which the CR would have more than 2X the area at the port exit.