Well if it slows you down at all, you'd better report it, or else you're likely to be fired for missing your performance targets.

Would it then be reasonable to fabricate injuries in order to game performance assessments?

I actually work inside one of Amazon's FCs on the West Coast. The managers in my department, actually encourage us to notify them if anything starts to feel out of the ordinary, in an effort to keep a little thing (overreaching instead of using the ladder, can cause shoulder strain, not bending at the knees can cause back strain, knee strain, not grasping product correctly can cause finger/wrist strain, even any of the physical effects of not staying hydrated while working) from turning into a big thing.

Is there no such thing as a "minor injury" then? Scraped my finger on a blister pack, better report it like I would a shelf falling down and crushing my leg.

If there is such a thing where is the line. I'd draw the line at anything that requires more care than can be provided on-site, IE you had to go to the clinic/hospital due to the injury.

I don't know if I would draw the line @ "than can be provided on site"

https://theintercept.com/2019/12/02/amazon-warehouse-workers...