It depends on the the subject, the exhibit, and the viewing distance. MF is frequently used to make prints up to about that size, and they usually work well. On close examination, you will definitely see grain and a lack of sharpness. But prints that size are generally viewed at a distance, and those defects will not be visible. Some subjects also tolerate them very well. Often, prints that size are not viewed critically but are rather used to convey an impression or to create an atmosphere for the exhibit. That also creates a situation where minor problems of sharpness are not as important.