Recently installed a syncros stem and realized that I needed a torx 25 bit to tighten the bolts.
Fortunately, I had the bit, but I needed various adapters to fit the torque wrench.
I went back to the spec, and nothing was mentioned about the torx socket head cap screws.
The next problem is if you are on a long ride or Brevet and need to adjust the handlebar or take up some play in the aheadset. You'll need the torx bit and a lever. To me this seems like a hassle.
Usually, with a couple of allen wrenches you can handle all the bolts on the bike.

Does anyone know a good reason why unusual bolts were used?
Thanks
YannisG