Haven't heard much from the aftermarket at all. That said, it could be worse, they could make one as hideous as the one they slapped on the Maverick... 💩
IMO, I'd just strap down a dog kennel. As long as it has a roof, probably enjoy it being more open anyway for the breeze.
Or you could also unbolt the tub that goes under the seats, fold the seats up, and toss in one of those "dog hammocks" in the back. If you want a soft and completely flat floor, you could even throw down some of those interlocking foam square things cut to just the right size stacked up to the appropriate height on the left and right of the hump. Easy enough to pull out and throw in the bed when you have rear passengers: