I use it the git aspects of it heavily for projects where I get lazy and should be using proper secret storage (for example Ansible playbooks with secrets not secure...). This is far from ideal, but makes personal development a great experience.

Secondly to that, we heavily considered and trialed it a work to unseal Hashicorp Vault. You can add a single identity that is able to unseal, and having that person verify in the keybase-esque method is a great idea.