From my understanding no players cannot deactivate the Volcano in Goroma during the Mini World Change - Fire from the Earth. The reason being is because then it would be a World Change in my eyes. Mini World Changes happen random and cannot be triggered by players. I remember when Lightbearer was happening we were all cringing at this mini world change xD If there was a way to stop this mini world change trust me we would've killed this place for hours. I've personally never tested this out myself but there's no proof as far as I'm aware.