Just finished reading the book, I loved it despite the ending gave me mixed feelings. Here's what I hope they'll add in the film version

The Eridians managed to get Grace in a cryo sleep and sends him back to earth. Grace successfully returns to earth and finds out the beetles worked out well, back to normal; him and Stratt get a Top Gun Maverick style reunion, they reconcile.

I decided to bring up that kind of ending because their final conversation was heartfelt and poignant which lacked closure.