zenki axles will slot in kouki centres fine, until you start going places.
they will strip the teeth like a piece of cheese (soft cheese like Brie or Camembert) because the interference is not tight enough.
kouki axles will not fit in zenki centres because they are simply alot larger (in diff terms).
it just dont work yo.
mind you, your question asks if anyone has tried this, and to answer your question no i have not, but this is what i gather would happen.