By the way - I found an interesting paper here: https://www.researchgate.net/publication/2813507_Deriving_Structural_Hylomorphisms_From_Recursive_Definitions
They show an algorithm for converting a large class of recursive functions into code that just calls some hylomorphisms.

This is interesting because, with a size-limited hylomorphism, we can finally ban runaway recursion, and yet write recursive code more or less freely.