[Cm452]

I've got a mixed bag of injectors: 6,8,9 indexes, ~2 of each. I know the 9s are of I'll reputation, but, the car runs well otherwise. Consensus seems to be a perfunctory change up to index 12s, but I'm curious as to the actual risks of popping my motor with a tune and older injectors ?
If one of my injectors fails by leaking, I can handle that. If it fails at WOT by going super lean, that I cannot.
I guess what I'm asking is how common it is for injectors of those indexes to fail catastrophically?
I've used the search function, but there are a lot of parrot posts without any explanation aside from "just do it".
Thanks!
-Cm