Second time Carlos Valdes (Cisco) is absent from an episode, the first was News Flash (2018), although a photo of him (as Vibe) appears near the end of the episode.
Carl Bork says "You can't hurt Bork, but Bork can hurt you!" This is the exact line that Bork says on the cover of The Brave and the Bold #81, starring Batman and the Flash.
Andre Tricoteux, who plays Carl Bork, was also the suit-actor of Savitar in season 3, and made several small appearances in episodes of the Arrowverse.
First physical appearance of Shawna Baez, aka Peek-A-Boo, since the season 4 premiere The Flash Reborn (2017).
Officer Jones was hypnotized by meta-tech, a reference to Spencer Young in News Flash (2018).