Question 1: If my interpretation of the movie's plot is correct, it means there are two versions of grown Shoko: one with Sakuta's heart and one with Mai's heart, yes?

Question 2: What led to the plot of everyone forgetting about Shoko? And how did she manage to stay alive when future Sakoda stopped Shoko from receiving Sakoda or Mai's heart transplant?

I'm sorry, but what movie are you referring?