Reverencing the altar

In Paul Turner's Blog by Paul Turner

Q:  At our parish, cantors and lectors bow to the altar on their way to the ambo, but not on their way back to their original places. It is felt that reverencing the altar twice is redundant. What would you say is correct?
A:  The Ceremonial of Bishops #72 says, “A deep bow is made to the altar by all who enter the sanctuary (chancel), leave it, or pass before the altar.”  The way I read that, it would be preferable for the ministers to bow to the altar on entering and again on leaving the sanctuary.