You’re in a great position to benefit from Green Belt Certification. Taking the course will help you to teach others about “symptoms” vs “root cause.” Often QA is focused on quality measures and immediate solutions to defects, but not always solutions that get at the root causes of defects. The Lean Six Sigma tools and concepts give you the best of both worlds. You get the variation and defect reduction of the Six Sigma world, and the removal of waste and streamlining of the Lean world. When you put these two toolsets together you learn how to truly engage with process participants to solve issues. In the QA world, these are exactly the skills you want on your resume.
This also puts you in a position to mentor others as you help build the problem solving muscles of those around you. Tackling process issues gives everyone a chance to “fix what bugs them.” That’s a satisfying thing to do whether you’re in QA or not.
It’s not a fluke that people who opt to become certified Lean Six Sigma practitioners are often the ones tapped for leadership positions. The habits you form around collaborative problem-solving simultaneously build your influence skills. Those are good life skills for everyone.
I hope that helps, and good luck in your endeavors!