The author answered himself: > Want to do something slightly off-script? That’ll be three trait bounds, one custom derive, and a spiritual journey through src/

The author answered himself: > Want to do something slightly off-script? That’ll be three trait bounds, one custom derive, and a spiritual journey through src/internal/utils/mod.rs An alternative is: you want something off-script, go fork the repo with the crate and patch it to accept your use case.