I’m not in front of my MnM right now, so I can’t confirm for myself, but, is there not some overlap of octaves on the keys when switching octaves? I think there is, and I wonder if this makes marking the notes on the keys obsolete once you’ve changed octaves?
I can’t play the keyboard in a traditional sense, so I just use the trig keys to hunt and peck tones, making melodies the best I can. Marking notes on the keys would be a waste of time and easthetics for me 