I've seen repo's use them as a way of categorising the type of commit (don't have an example at hand), which could be a good use if used consistently and the categories fit your workflow.
I use it for a CMD Resume (https://github.com/bbody/CMD-Resume/), honestly though I can only think of one time the emoji helping me find where I broke something quickly.
I followed (https://github.com/slashsBin/styleguide-git-commit-message) but more recently started using Gitmoji (https://gitmoji.carloscuesta.me/).