The closest comparison I have to this is reading in school where it became very obvious who the fast, skilled readers were and who had to work harder to understand the text, which caused a lot of anxiety for the slower readers (which didn't help).
I can imagine a wide variety of possible outcomes for this, from accommodations being made to people just being a lot more mature as adults, but I'm also guessing there has been some trial and error about this at Amazon and some best practices have emerged.
Does anyone here know what they are?