Yes, I've been using the USB output in the THR30II instead of the Real Tone Cable since I bought it almost a year ago. First I used it using the Microphone input option (for acoustic guitars), but now there's a mod that adds an option in Rocksmith for interfaces (Direct Connect). This way you also get Rocksmith's "real" tones (and better detection, actually). The wireless transmitter, Relay G10T, has very low latency, so I don't really notice any gap. Playing without cables is awesome!
In THR Remote options, make sure that Record Dry is ticked, otherwise Rocksmith will detect the distortion, delays and so on. And I'd change USB OUT to 80-85 so that you get a nice signal.
If you need the mod, check the last post in The Riff Repeater.
Should anyone be interested. My THR30ii arrived today and I was eager to check out Rocksmith with the Line 6 G10 wireless dongle. I plugged the Rocksmith cable into the line out port on the back of the amp, selected a tone and powered up Rocksmith.
Pleased to say it works a dream. I’d previously bought an ABY splitter to play via an amp but this cleans the set up nicely.
Wireless freedom is a joy. Playing Iron Maiden whilst strutting around the kitchen without any lag issues is a revelation.