What is meant by “come down on the level”?

Do Brothers seated in the sidelines have to come into the main working area of the Lodge to be “on the level”?

The instruction to “come down on the level” is found in the Lodge Opening and Closing Rituals as well as the conclusion of the Middle Chamber Lecture. From a purely technical standpoint, the only parts of the Lodge that aren’t on the level are the stations in the East, West and South. However, when the Ritual calls for the Brethren to come down on the level, all those present should leave their seats and come into the main working area of the Lodge unless it is impracticable for them to do so. What might make it impracticable? A physical infirmity or ailment might make it impracticable for an individual Brother. Or if the Lodge is unusually full, it may be impracticable for those in the second row of seating to come into the main working area of the Lodge due to an insufficiency of space to accommodate that number of Brothers. If it is not legitimately impracticable, all present should come into the main working area of the Lodge to be “on the level.”

“Impracticable” in this use means “extremely difficult to achieve due to practical problems or issues in opposition; effectively if not technically impossible.”