Why did Flash use Elongated Man instead of Plastic Man?
The powerset would have been similar but actually more comical, which would have worked well for the show.
Since they wrote him to be a disgraced police detective turned PI, the idea of him being a cop became rather irrelevant. Now if he had been an ex-criminal, as Plastic Man, his redemption arc would have been much steeper.
I just feel like Plastic Man would have fit the overall vibe better.