
How I'd continue this Peter Parker's story.
Since "616" Peter Parker is suffering from radiation poisoning due to the physical laws of "Earth-1610" and possibly has months to live at the end of What If...? Secret Wars 2026. If this issue were to get picked up as a mini series, I'd have it that both Stark and Banner survive the Triskelion's destruction and either one work with Peter on a cure for his condition. Peter would reconnect with this universes Aunt May and ask her to contact her Peter Parker to see if he could help him.
Due to "Ultimate Peter Parker's" DNA being altered to the OZ enhanced spider, this would bring the opportunity for both Peter's to meet each other that we never got to see in the main comics. During the time of running tests, "616" Peter would connect with his counterpart and his Mary Jane and talked about the events they've been through their lives. I'd bring in Gwen Stacy as well where he tells her the truth on how he lost his Gwen Stacy to his Green Goblin years ago and was just glad that there's one universe where both of them are still alive together. To help "616" Peter, I'd start with purging his radioactivity before "Ultimate Peter" gives a blood transfusion. Before the proceeder "616 Peter" would tell his counterpart and his loved ones that even if he didn't survive the procedure, he'd be glad that he'd die surrounded with counterparts of the people he loved.
The procedure succeeds, and "616 Peter's" genetic code is stabilized by the OZ formula, and his body is entirely synchronized with the "Ultimate Universe". After some time, he returns to a more active role working with The Ultimates to rebuild the world.