Finally got around to looking into this, and as far as I could tell, the solid-fluid items are definitely visible in every logistic and circuit interface I could find, and the melting recipes were also visible in the circuit interface, but I could not find the freezing recipes in the same interface. Not entirely sure why... it's possibly something to do with the solid items themselves? Though they aren't hidden or anything, so the recipes shouldn't be hidden either.. I don't know.
It seems like a minor issue anyways, so I'll have to mark this one as Unsolvable, sorry.