Always account for leg space, overhead and breathing room. Just because a camping toilet is small and portable doesn’t mean it needs to go into the smallest space possible. An area that has vents or a window is perfect since you don’t want it in a place where there is no airflow. Lack of airflow will allow smells to amplify and become worse than what they are.
You’ll notice this the most when you go into the area where the toilet is and open the door- the smell hits you right in the face. Buyers that plan to put the toilet in a semi-open area will get the best airflow, and possibly the best experience. As long as the location you plan on putting it in has a way for odors to escape and ample legroom, then you can consider it a good spot.