Someone used the thicker black O-rings on my rig, (late 12 bolt rims) managed to warp one of the rims to the point I had to replace it, I think this is common practice by some but I would suggest only a person with nothing to lose should do this as this is a litigious society and a lawyer would have a field day with that, If the rim will not seal with the factory oring and using factory procedures it should be replaced or that person is likely to be liable.
EDIT, as a side note, I visit with a guy in Corpus Christi every now and then that is custodian of a large warehouse that has a collection of some of the worst wrecked vehicles I have ever seen, all had extremely serious injuries or deaths involved and all are under litigation (It is a "pool" location for ins. companies)
He says about 75% are tire failures and of those about 60% are Cooper variants (if it does not have a major brand on it, it is probably made by Cooper)
The lawyers come down and take pictures, have "experts" dismantle and inspect them etc. He is lonelier than the Maytag repairman and always enjoys talking about them, and they constantly change as law suits are settled