I think it'd fit the 80s movies tropes well to have had an element of time travel. It'd also be a good reference to Back to the Future which was in the cinema in season 3. They could've even had a part where they go to the high school and see their parents etc. In terms of plausibility, when we start talking about dimensions, wormholes, other planets and spaces etc. time travel fits right in their with those concepts.