Mag cleaners are more effort than a short bit of attention with a kent blade. I agree with you Mark, I'm not on the "shallow" bandwagon... And one of my fav tanks ever was super deep... But, in practicality, with limited time, I'd advise against that depth.
I don't know about you, but I can clean the whole tank with my mag float (and scraper attachment) in a few minutes once a week. As for knocked things, I am more proficient with my tongs than most apparently, as that is easy (would use them for short tanks too)
Mark