The next episode, "Hollywoodland", is shamelessly ripping off a Legends of Tomorrow episode as the team goes to Hollywood in the 40's to save Hedy Lamarr.
Given how close together they were made, there's no way it was a "ripoff." Timeless season 2 may only be airing now, but it began filming back in November, and since "Hollywoodland" is only the third episode, it was undoubtedly written months earlier, probably during the summer, since the show got the season 2 order back in May. The "Helen Hunt" episode of Legends didn't air until November, by which point the Timeless script was surely too far into pre-production to abandon. It's the kind of accidental parallel that happens quite frequently when different shows are drawing from the same pool of concepts and subjects, and that creators generally try to avoid if they're aware of it. Nobody wants to be accused of imitation.
In the case of the Hedy Lamarr story, it's been part of popular awareness for many years now. Ever since cell phones became a major part of life, the story of how they depend on a wartime technology invented by a gorgeous movie star has been frequently told. It's a romantic and unexpected story, it involves Hollywood glamour, and it's a great story to tell if you want to showcase the overlooked achievements of women in history, so it's not at all surprising that two current time-travel shows would use it. Indeed, a feature documentary about Lamarr's career, Bombshell: The Hedy Lamarr Story, debuted at the Tribeca Film Festival last April. So maybe both shows' writers were independently inspired by the film and the new attention it brought to Lamarr's story.
It's not even the first time the shows have used overlapping ideas. They've both done Apollo-program episodes, although Timeless focused on Apollo 11 and LoT on Apollo 13. They've both done Al Capone episodes. And there will surely be other parallels as the shows continue.
Aren't they more ripping off Agent Carter's storyline of a pseudo Hedy Lamarr character, only this one was a bad guy?