The most interesting things about Conventional Commits are that they can be deterministically digested by a process to decide how to bump a SemVer and similarly to create a formatted CHANGELOG file.
I really wished we had type systems good enough, and tools smart enough to figure the semver bump by it self. Ideally humans should not come near semver bumping, not even through the commit messages.
Elm does have a type-directed version bump tool. Is that what you were thinking of?