To my knowledge, SHA-3 uses a sponge function, allowing it to have arbitrary length.
Will there be a version of scrypt which replaces the Salsa stream cipher and the use of SHA256 and replaces it with SHA-3? While I'm not sure of the die area of SHA-3, it does require as much RAM to run as SHA-256 (
https://eprint.iacr.org/2009/260.pdf), but that can be remedied by standardizing multi-kibibyte long outputs and using numerous iterations.