I can’t speak much to the security, though I’ve used it for a couple of years without any indication of security issues. They don’t seem extremely popular, so they likely aren’t a very common target, but that also means it’s hard to know how vulnerable it is.
I haven’t done any traffic analysis so far, but would be interested in it. If someone does come up with a way to run it locally, I would be happy to expand the integration to support different endpoints.