About as much as I trust the aliexpress Ti bolts without the mount. The mount loops have the same function as a split washer, so maybe they even improve matters?
I always tighten the bolts with the short side of an allen key and put my full weight on the end of the drops, and there is no difference with the mount - no movement. The bolts (1mm longer than stock) engage the stem threads fully.
If I was sceptical, I could rotate the face places and use the side that interlocks with the stem body (a Kalloy Uno feature) for the mount, together with steel bolts. This would allow me to use much higher torque without putting undue force on the bars - since this is adjusted with the two bolts that leave a gap between body and face plate.
However, for aesthetic reasons I left the gap on the lower side.