Awesome! I actually contemplated going that route as well, but obviously decided not to. Cool use for Lambda though. Do you find that people are using that feature?
Some people are, but mostly just a hardcore few who are using protected branches on GitHub. I expect usage to tick up as I ramp up (in app) marketing for the feature and move upmarket into larger companies with more formal development workflows. But also, this was an investment in infrastructure that will allow me to offer other deep customizations later on.