Proof?
The above two excerpts seem to demand it.
My employee is a former QC for Pegatron, ASUS, and Acer (They all make their own monitors too)... Pegatron is a contract manufacturer for Apple products including the macbooks, iPads, and iPhones.
Here is what she can disclose to me without violating the NDA of her former employers:
Each company has different criteria (Handbook) for acceptence of the batch of LG Panels - it could be no defects/dots and or must meet a particular brightness/contrast ratio, etc: It is either REJECT or ACCEPT: Apple - For example when the Panel batches arrive to factory for assembly they FIRST do a statistical sample of each batch. If the samples meets the Criteria guideline then they accept the batch, if not they reject the entire batch. Then during assembly before packaging they QC every panel to see if it meets the criteria, if not they pull that monitor from the line for their engineers to inspect and have it replace with a panel that meets the criteria. If more than 3 panels during final QC fails the criteria they stop that whole line to inspect that batch. All rejected panels are sent back to LG for replacement. Also all display panel batches are accepted by factory on consignment so they always return rejects found later in return for Accepted passed panels later.
Apple does check every panel before it leaves for market.
The REJECTED batches may actually have A+ or A panels in there, but it is rare due to the manufacturing process for that batch.
What may be rejected by Apple, may be accepted by other brands/factories... Other brands may accept higher/lower brightness and or different contrast ratios or accept a bearable amount of defects (like backlight bleeding) - but they all have one thing in common, 1 dark/dead pixel deams the entire monitor as defective. But this is how Apple and big brands gets the pick of the best panels (A+) and leave little A+ panels for everyone else whom may inspect every panel in the rejected batch to find these flawless panels.
Major brands that have their products sold at major retailers would not accept batches with visible defects/etc because their distribution partners would not want customers returning/rma... the industry standard is 5% or lower. Which explains why you don't see Catleaps or other Korean brands in major retailers.
The Catleaps and other Korean factories are willing to accept LG panel batches with max 5 or less dead/defective pixels/dots - and the sellers have said some blacklight bleed is okay = these may be Apple rejected batches due to their initial statistical inspection and it doesn't necessarily indicates that entire batch of LG panels share the same rejected characteristics, may be a majority of them are perfect panels with no or little defects - which explain why some customers receive monitors with little or no issues. For the price people are willing to take the gamble or accept minor stuff and its suitable for their needs such as gaming...
I am still trying to find out and researching the criteria for the grading of panels. Which is why I'm hoping for a factory/brand representative that is trolling these forums can share this insight...