Rian Johnson gave his good luck charm a similar role in Knives Out: a voice coming from Marta Cabrera’s (Ana de Armas) television credited as Detective Hardrock.
Whatever his role might be, Knives Out 2 could benefit from a little extra JGL magic.
It might be fun if Joseph Gordon-Levitt appeared in the follow-up as a character with a little more physicality.
Maybe make him the murder victim that incites the plot, or an innocent, unrelated bystander who find the body, or even have him reprise the role of Detective Hardrock, who butts heads with Daniel Craig’s Benoit Blanc to be the head gumshoe of the investigation.