This is definitely a problem, but the place to solve it isn't Son.

Son is intended to be a very simple project that grabs all the clear wins. Do we really need both `0` and `-0`, stuff like that.

There are too many different things JSON Numbers can represent for us to have a clear strategy for all them in Son. Int64s, doubles, floats, arbitrary precision numbers (eg https://hackage.haskell.org/package/scientific-0.3.5.2), etc. That makes this a good for for the schema layer (eg JSON Schema or whatever you're using), not the base specification layer.