Not sure you can call yjis conflation. From what I've read that was a deliberate thought out decision and a nominal type system is as valid a choice as a struct

Not sure you can call yjis conflation. From what I've read that was a deliberate thought out decision and a nominal type system is as valid a choice as a structural one and generally better understood in research and industry. Having said that as far as I understand, type support in Ruby 3 will not prescribe which type checker is used and what limitations exist. Some of the mentioned projects are structural and I think even Sorbet might add support for it at some point.