Has anyone tried or explored the possibility of implementing the core.logic streams as reducibles or iterables and not as lazy sequences?

The way minikanren handles branches by interleaving makes expressing it as a reduce tricky

I think someone wrote a datalog in clojure based on reduce, Odin maybe?

https://github.com/halgari/odin

From chasing down the papers, isn't it the only way to guarantee fairness in the implementation?

yes