I could not just approach my employer and ask if I could help code this open source project

I've open sourced multiple (small) changes I've made to various open source projects on company time. Usually it's projects we use and where I've either fixed bugs or added a small feature that we could use.

Employer doesn't have to apply patchsets to our dependencies and doesn't have to keep them up to date. Everyone else gets the fixes as well. => Everyone wins. Employer sees that.