Absolutely agree. I completely disabled arrow keys for a short time; ~3 months. It started out after reading a similar recommendation. It was difficult for a few days, but then I completely forgot about my arrow keys and the fact that I disabled them. It wasn't until months later that I was in one of these situations that I wanted to use the arrow keys, but they didn't work. Which was confusing.
This must have been around the time that I started to understand, and manicure, my vimrc because I remember having to learn all the mapping modes to recover arrow keys for Insert Mode.
So, anecdotally, completely disabling arrow keys led me to learn more Vim than just efficient movement.
Today, though, I don't have the makings anymore because it's no longer a problem.
One quick question; I can't answer this because I am currently commuting. Does 'noremap' disable keys in Command Mode? Now, that would be aggregating, to me.
Also, there a remap mode that combines Normal and Visual modes (right?), that would be one better than 'nnoremap'.