So we're yours breaking at or near the very ends Tim? That IS where nearly all springs usually break. No matter what cars they are on. It's not because they are formed "more cheaply". Look at the springs on Mercs, BMW, Lexus & they are formed the same. Or mostly. If you flatten them, something that was done a lot years ago, they are not quite as strong. They still break. Do many don't flatten them now. Trust me. Spent years & years in the trade & have changed many a spring.
PS. Not to confuse them with motorcycle springs which nearly always use a formed end at the bottom because they are on show, mostly.