Agreed. I can't imagine that any meaningful percentage of Facebook users care about the HTTP spec.
JavaScript in modern web apps has made the distinction between GET and other HTTP methods irrelevant to users. Simply changing these "frictionless sharing" apps to use POST instead of GET doesn't address anyone's concerns.
Everything you get in the Network inspector in Chrome DevTools should be available in Headless Chrome.
https://chromedevtools.github.io/devtools-protocol/tot/Netwo...