"The Lost Martian" is too visually impressive to be a 1960s television production. It is presented in modern widescreen, the image quality is digital clear without film grain, and the special of effect of the alien with multiple arms is seamless, indicative of CGI and not the limitations of the period.
When going through Reggie's previous jobs it briefly shows him waterboarding someone, you can see the breathing tube going from inside the orange jumpsuit and under the towel.
At some point, Mulder starting with the concept of another universe, says that we could live in another dimension. But this is not the same thing. As we know, there are four dimensions but as theoretical science goes there could be eleven. Nevertheless, no matter how many they are, they all happen here not in another universe. So we are already living in them the same way we are living in the four others but without feeling them.