"Actually I do", okay, contrarian. You can't rewrite history because you don't like the outcome. You clearly have an ulterior motive, with all the sensationalism.
Thing is, no one's complaining about getting PETG shrouds except you. Despite the fact that if they made that mistake, there'd be hundreds of printers with that filament type.
Given that you've:
A. Provided a completely incorrect reasoning for concluding PETG
B. Repeatedly stooped to insults, making anything you actually say terribly untrustworthy
C. Later tried to backtrack out of (A) by saying you have other better reasons (if you did you would have said them instead, not after being corrected)
D. Bring up unrelated issues to MK3 as a cause for why this particular part, on only your machine, would be incorrect
I don't find any reason to trust anything you say.