Very sad to hear that the Chromecast won't work with NESNgo (and I presume the MLB network streaming service as well, as they seem to be pretty similar).
Besides Playstation Vue, which as I understand it costs money for channels I'm always getting for free (free cable via working for my cable company), is there any reasonable way to get this stream to my TV without my PC? The short of it is, the room in my house where I want to watch baseball doesn't have a cable box. I can put it up on the screen with my PC, but that's not always an option.
I've tried the PS4 internet browser, which would have been a clumsy solution, but that didn't work either.