Did Mork and Mindy’s family ever go back to modern times?

Question

I know that in the final season Mork and Mindy went back to prehistoric times. Now my question is did they ever come back to modern times?

Answer 1

We don't know but it's implied they would...

The cliffhanger ending to Season 4 was intended to kick off a change in direction for the show in Season 5

“We even tried to get a fifth season. So here was the scenario: [Kalnik], another alien, became Mork’s buddy, and then [Mork] finds out he’s there to kill Mork for some reason. And so, to fend off this threat, they revealed themselves to the public [as an alien and his wife], and ultimately they had to run away through time to hide from [Kalnik]. It was going to be a semi-educational show, where Mork and Mindy traveling through time would meet with historical figures. We actually did a photo shoot for that, of [Mork and Mindy] standing with Abe Lincoln and Benjamin Franklin.”

^Source

Unfortunately, the show was cancelled and the "final" episode "The Mork Report" which had actually been filmed before the 3-part finale was shown out of order to give the show a more appropriate closure feel.