All great info on cracks and repairs. And of great interest.
However the info I’m trying to get is the percentage of early cars that have cracked. I spent some years dealing with weld procedures. So I know that there are many variables in the process making some more likely to fail than others in the heat affected zone. It may be that 10% were destined to fail due to the method and the welder that day or that batch.
I also note that the redesigned top brace cones loose easily rendering it useless. So maybe no need for sleepless nights. Ensure the triple brace is tight and it could be a 9:1 chance in your favour.