For as long as there has been talk about a canal through Central America, there has been talk about the route through Nicaragua. It’s longer, but lower. It would be easier to build a wider canal; it’d even be possible to build a sea-level canal.
Whether it is economically feasible, though, is something else entirely. I’d expect not.
It would be one hell of a dig.
If they do dig such a trench, I hope they maintain a fresh water barrier between the two saltwater basins.