The first big action set piece in "Fast X" takes place in Rome, during a mission led by, appropriately, Roman. He, Han, Tej (Chris "Ludacris" Bridges), and Ramsey (Nathalie Emmanuel) are tricked by Dante into stealing a bomb, believing that the operation has been commissioned by the Agency. Through it all, Roman constantly asserts his own abilities as a leader and takes offense every time the others doubt his chops.
While not necessarily an intentional reference, this little arc for Roman is interesting given his history in the saga. He first appeared in "2 Fast 2 Furious" as the replacement for Vin Diesel, who opted to film "The Chronicles of Riddick" instead. In another timeline, that could have led to Tyrese Gibson being one of the two leading co-stars for the series and Roman quite literally being the leader of the crew. But instead, the character became (admittedly great) comic relief under Dom's shadow.
For fans of the "2 Fast" era, it's fun to see Roman getting a bit of development on the leadership end. Gibson is still more than capable of stealing scenes on his own, and he gets some solid material in "Fast X," though nothing on the level of "Eject-o seat-o, cuz."
There is a more specific "2 Fast" reference later when Roman reveals that he keeps cash strapped to himself under his clothes. He pulls the exact same move at the end of the second film, much to Brian's amusement.
