Midnight, I pulled and replaced the brace no problem, bike on the ground and everything. I did so after I observed that the brace engages the swingarm at both ends, no way belt stresses could torque the swingarm out without it (at least not for a minute or two)
Onelogue, I've had success finding a torx wrench that snugly fits into a stripped socket head, then going to the next torx size up, tapering it on a grinder, and then driving it into the stripped socket head with a hammer. (the torx should be a socket style) use a length of rod behind it to hit with the hammer. I used 1/4" square stock that fit the back of the socket. Then once it's in there really good, I carefully and slowly applied torque with a small ratchet. You should test your torx "tool" on another stripped socket head bolt of the same size in a vise. Make sure it doesn't split the head open when driving it in, and see how much torque it can take as well. Then you'll go into it having a "feel" for what you're doing.
Mine weren't torqued that tight, you may have been indirectly pulling the wrench.