I think that there is a difference in what is "a lot of back-to-back roasting."

The reverse airflow and accompanying mods were from a time when people started businesses with a Hottop. Today's choices in roasters simply didn't exist. So, for example:
- starting the next roast as soon as the current roast is ejected to the cooling tray, aiming to get close to five roasts an hour;
- roasting continuously for four-five hours, so 20-25 roasts a session;