So I really like "Radar writes the in-universe version of MASH" as a headcanon, but Frank writes a thinly fictionalized memoir of his time in the 4077th to inspire a future generation of Army doctors and it becomes a smash hit in the 60s because people think it's a satire when it's really just his incredibly skewed perspective.
His protagonist Ernest Frost is a tough no-nonsense country doctor who learned frontier medicine on his pappy's knee and has to learn how to work with hot shot draftees from the big city hospitals and their fancy shmancy techniques. He either amalgamates BJ and Trapper into one character ("TJ") or he like just switches the characters half way through (JT becomes TJ) and spends like half a page explaining then never mentions it again and people think this is commentary on how the army turns everyone into replaceable cogs. He writes himself into a tragic love triangle between Ernest's loving but cold wife and the passionate but unpredictable nurse he meets in Korea, but critics always note the homoerotic tension between Ernest and his bratty rival "Pathfinder Polk". Some well meaning high school freshman sends him handwritten gay fanfic about his self insert and his Hawkeye expy and he literally has a stroke. He's portrayed by Alan Alda in a popular TV adaptation of his novel.
