The torque limitations are based on the standard CVT style. However, a "chain" version was patented by Larry Anderson that would allow for extremely high amounts of torque based on a chain instead of a belt. The system used "floating sprocket bars" that would allow dynamic sprocket distance selection between the chain and sprocket. Built out of strong metals, this would prove to handle over 1000Lbs/tq.
Anderson was working on fatigue testing last time I'd talked to him. I think his son took over the project and they were scheduled to talk to some large auto manufacturers (I believe GM was one of them). I don't know what happened after that, but I've seen videos of the prototype working and it's pretty interesting. His domain has been taken down since, so he may have sold the patent and it may have been buried.
You can see the prototype of it at 1:17 in this video:
On a side note, CVTs are pretty boring, but if you couple it with an electric motor producing a lot of torque, it'd be far less boring because it'd be a "hold on tight and hit the gas" type situation. Personally I prefer a manual over anything, but there's pros and cons to everything.