There is some good info now available on www.buildering.net about roped sololo devices.
Did you know that an Ushba will cleanly sever the rope at a 5 kN force level!! So its safe to use for TR (max realistic force you will gennerate is about 1.8 kN) but NOT for leading
If you can find a Troll copy called a Roller, it is safer, begins to slide a bit a 3kN and so does not cut the rope, apparently.