(Yes, most of us associate isekai with being reborn in another world that is conveniently in RPG style because hikkikomori wish-fulfilment, but the genre has always been broadly defined as going to a different world, virtual ones included).
Kenji as an isekai protag will most likely be similar to Kazuma, but without the pervertedness and asshole qualities that make me wanna punch him in the face.
And man since chapter 80, this summer break arc has had so many mini-arcs: the St. Tachikawa rematch, the East Fuge High infiltration, the absolute madness that is Kenji's dad coming home, the Shibasaki's groundbreaking ceremony, visiting the Takao household, and now an isekai arc. I'm certainly not complaining though.
The prez: "Hello, would you like to come over and play a new game?"
Takao & Funabori: "...Uhhh"
The prez: "With the Kazama household"
Takao & Funabori: "You son of a bitch, I'm in!"