I do agree human judgement based bounds are best, but stackage snapshots aren't that. Furthermore, stackage/fpo LTS is not LTS in the same sense as linux-distributions and their BSD-unix cousins. Proper long term support in any meaningful sense is a commitment by the distro provider to backport security/bug fixes to the LTS. Stackage LTS doesnt do that.
stack tricks its users into not thinking about their relationship with their dependencies and poisons library code from being usable by haskell devs/users/contributors who dont use stack. :)
the more you know! :)