It does have ideas never raised again. Gary Seven could be human, but he's also a product of generations of humans raised by an advanced race on another world so maybe there was tinkering going on that makes Seven look mostly human while being something more.
The transporting across vast distances idea is visited again in third season in "That Which Survives" when theEnterprise is transported across a thousand light years.
The time travel to do historical research idea might have been the first time they had actually tried it, but it doesn't answer whether it would become a regular thing. Seems to me using a Class One starship for this kind of thing isn't the greatest idea. If you're going to do it I'd think a small dedicated team would be better.
The episode itself is just okay. I think it's not something they would have done if GR hadn't wanted to do a backdoor pilot using Star Trek
as a jumping off point.