Anyone who takes up the mantle of Chadwick Boseman should look similar, should remain dignified throughout, portraying a powerful warrior with some weaknesses but a strong king.
I don’t see anyone doing that but Chadwick Boseman.
And homage would certainly have to be paid to Chadwick Boseman in that we see him in the film.
Maybe the movie should start with the last scene of Black Panther where the kid approaches him on the basketball court.
Then we see the news of TChalla’s untimely death at a young age, but how much he was able to accomplish for the inner city.
Perhaps a black man who isn’t Wakandan is allowed to attend TChalla’s memorial service (maybe Shuri fell in love in the US)
And he ends up saving Shuri’s life. Now there’s a power vacuum. Mbaku tries to keep things under control, but Wakanda has become divided. Which allows the villain, whoever it is, to exploit the situation. Eventually things get so bad that Bast visits the black protagonist and provides him with the powers of the Black Panther, thought to be gone forever after Killmonger burned down the source and the last bit was given to TChalla. When he enters the realm of his ancestors (we notice former slaves in this realm although it’s not harped upon and they stand next to kings), he suddenly sees TChalla (digitally rendered) who doesn’t say a word, but passes the mantle on to the new Black Panther with a smile. The new Black Panther, with the help of Mbaku, Shuri, Okoye, and Nakia unite Wakanda against the villain and defeat him. A monument is built to TChalla and when the elders decide on MBaku as the next ruler of Wakanda, he relinquishes the throne, giving it to the Black Panther chosen by Bast and TChalla.