About 3 weeks ago, a member posted that he ripped the wires out of his torque sensor during some mishap. When looking at it afterwards, he discovered that if he joined two of the wires, the motor went full-speed, like a press-button throttle. He then tested it on the road and made a video of himself doing 20 mph without pedalling. He didn't say which two wires. If you can find that thread or posts, you can message him to ask which wires.
Can anybody provide a link to those posts? I can't find them. They've changed something in Google, so it doesn't find anything now. It used to be very good.
I don't have a Gtech, so I can't test it, but my guess is that he connected the torque sensor signal wire to its supply wire, which gave the equivalent of the maximum torque sensor signal or even higher. It should be possible to put a push-button switch between those wires to give you a push-button maximum-only throttle that will override the normal torque sensor operation - like a boost button. In the interest of science, we need a brave person with a Gtech to prove whether it works. I'm 95% certain that it will.