I was a member of the stress riser club until
@Tadem posted his pics in #1034. It clearly shows the tank material being significantly thinner at the bottom of the small vertical edge.
Probably some issue with how the plastic is injected and molded. I do believe repeated stress in that location makes the situation worse, but as good of an idea as spreading those forces out is, there are variables like the material used and it’s ability to deal with the conditions and application... and it might not hold.
And IF your patch doesn’t truly hold and disperse the forces it IS hiding the crack propagating. Sorta like if you don’t get your holes drilled at the very end of the crack.
Edit: the very fact that Tadem was able to cleanly remove his patch without damaging the underlying material means they don't stick on there all that well. At least not in a way I'd regard as becoming an additional part of the tank structure.