So I think the average recommendation is 4 hours, but that’s mostly because there are people who will do less. It’s not necessarily their fault, in many cases their living situation/work schedule just isn’t set up for more. However, I agree with Sarah that it’s not really all that much. It sounds like you’re really trying to give Oreo what he needs, which is so sweet of you. That cage is pricy! And your carpet…that’s no fun. But when you let Oreo out, you should let him roam around a much larger space than just the tiny “play yard”. And that’s the manufacturer’s fault for promoting such low expectations! Unless your bunny has a bigger space to run, he’s going to be stressed.
I had to experiment with habitats too, and it kind of seems like the bunny chooses. Mine is free-roaming, using the open cage just as a “safe place” and to use the litter, but I recognize not everyone can make that work around the house. So my suggestion to you is this:
1. Measure from the back of the cage to the furthest opposite point of the yard fence, to get a length. And from the leftmost point to the rightmost point of the play fence, to get a width.
2. Get a crappy but durable rug that you don’t mind looking at on Craigslist (or elsewhere), it should be a little bigger than your measurements.
3. Put it under the whole cage and play yard.
4. Bunnyproof the room!
That way, you can leave the cage open to the play yard 24/7. Let him run around the room (supervised) for that 4 hours, then when he goes back to his space he will only be able to tear at something you don’t care about. Giving him more freedom will help with the stress, though, so he may stop doing it period.
Is there a couch and tv in that room? I watch an hour of tv a day when I come home, and I feel like this is a great way to multitask. She knows what’s up. As soon as my butt hits that couch, she hops up ready for pets! Just saying, that’s a whole hour you just killed making your bunny happy with zero effort. Maybe that’ll help Oreo!