The t239 has a different ampere arch type than t234, with a different number of SM's in a GPC. Because of that you won't be able to emulate it's render config using this, you'll always be over/under.
A YouTuber has come up with an interesting solution for a potential Nintendo Switch 2 dev kit solution, but it will likely be too costly for anyone who fancies knocking up next-gen Mario Kart. In addition, a Nintendo executive has been talking about the company's future, with numerous sites pulling Switch 2 clues out of the context of the interview.