Funny you say that, because I have an old laptop that has a native VGA output on board and I'm testing it out right now! It works and Mint outputs through it just fine, but I'd need to get a VGA to composite adapter. Buuuut, if I'm gonna do that, I might as well just get an HDMI to composite adapter for the compatibility.
Also, any USB to composite/s video/component adapters? That sounds like a great workaround.
Also yeah, I know latency will exist, but it can always be minimized.