OK. Read the OP, and haven’t really read the rest, so apologies if this has already been sorted.
Thats really poor and uneven wear, which cannot have been caused by incorrect pressures. Having spend a more than a decade in the fleet industry I have seen this happen many many times. Dealers will ALWAYS try to wriggle out of this, but will always either give in eventually or when a complaint goes to the manufacturer.
Correct observation by one that tyres are not covered by warranty, kinda true, but not strictly true. They are: firstly they if if they were the OE tyres and were manufactured incorrectly, and secondly (in your case) they are in effect covered by the warranty because a fault with the car has caused them to wear incorrectly causing you a consequential loss.
Mercedes, VW, Mercedes, BMW, Renault, Land Rover, Mini, Saab , etc etc- I have either had them done on warranty on my own car then re-aligned by the dealer for organised it a customer (I have lost count), give them hell and don’t budge. Its not your fault, so its theirs, simple as that. If you need any more info/guidance please feel free to email. You may have to excavate higher int he dealer group or to the manufacturer. Or sue as a last resort.
Incidentally that can be caused by too much negative camber, but could just as easily be caster, toe or all.