Best way to judge draw consistency over time?

What is the most useful way to document draw consistency without pretending every device is identical? I notice small changes over time but have trouble deciding what is meaningful enough to mention.

Do you look for a sudden change, a gradual shift, or just whether it becomes distracting in ordinary use?

I would record the baseline first, then note when the change becomes repeatable rather than a one-off. The useful question is whether the change alters normal operation or the way the device needs to be used.

A gradual change can matter too, especially if it appears alongside a change in output. I would avoid turning every tiny variation into a defect, but a consistent trend belongs in the notes.

That helps. “Repeatable enough to change normal use” is a better threshold than trying to score every small difference.