Question:
Can the auto comment feature respond to Facebook groups that I do not own?
Answer:
First, Facebook Group commenting is not supported by Facebook. There's no official API provided by Facebook that does this.
MMIO is not a browser extension, rather we are a “web application” that purely uses Facebook approved APIs which is why we do not have that feature.
However, you can use “browser-extension-apps” that makes it possible to do group comments.