Hi Again, Things changed much quicker than I thought, and Dominic has just responded ( https://github.com/DomBlack/php-scrypt/issues/62#issuecomment-1183262246). That said, I'm happy to contribute to the original extension, so that we don't have to create a new repo under the PHP org or a PECL package.
Thank you, Remi and Christoph, for the suggestions! Máté