For different minor versions and builds of libraries?

This is basic paging and CoW (Copy on Write) behaviour. I agree, it's mostly a non-issue

That's only the case if the libraries loaded are identical, It won't work with slightly different versions of the same library (unless the differences are small and only replacements, so the pages remain aligned between different versions), and that case is very unlikely to be solvable

The parent comment doesn't talk about different versions and I wasn't either.