I thought I heard that all the broncos essentially have the holes that the washout floors use, but those with carpet just run over it (I would also assume no 'easily removed drain plug' under the carpet), but I think this at least opens up the possibility of a conversion/aftermarket situation that is similar.
That said, I haven't heard of anything existing already, but nothing stopping you from taking a peek under that carpet and coming up with your own attempt? But maybe your garage isn't filled with your half done ideas like mine haha