It is a little misleading. The screws in the mounting plate have proper Posi-Driv heads, with the tiny extra grooves, between the main cross. The adjusting screws are indeed made to use the same tool, but they don't have to. A properly sized slotted screwdriver will turn them too. This may be to simplify adjustment for the "average Joe homeowner", who probably does not own the correct tool (Posi-Driv) It doesn't require much force to turn them.
I certainly can't speak for Europeans, but in the US, it's almost guaranteed that they don't have a PZ-2. Most wouldn't even know what it is. JIS is even more rare here.
@ReneS It's a bit of an oversimplification, but the main difference between Phillips and Pozi-Driv is the shape of the blades/wings/lugs of the cross. Phillips is tapered in all directions. This does several things. It makes insertion of the driver tip into the screw easier, but the main point is "cam out". This occurs (intentionally) because the two tapers are fighting each other. After enough driving force is applied, the driver "climbs up" the tapered face. This is why drywall guys use them. It becomes a self-releasing situation. Once the screw is in deep enough, it will not go anymore, the drive just slips.
However, that is not the desired outcome in a whole lot of other uses.
Posi-Driv looks essentially the same, with 4 driving lugs, but they are not tapered. The driving faces of the driver tip are perpendicular to the rotation of the screw. They do not cam out and the fit is much closer. Thus, it takes a little more care to insert the driver into the screw.
A Posi-Driv tip probably won't even fit into a Phillips screw head, unless it is really worn, and Phillps drivers chew up Posi Driv screws.
JIS is quite a bit closer to the Phillips shape. They are sharper in the bottom of the flutes and slightly smaller overall. They would be loose in a similarly sized Phillips screw.
Nerdy over-explanation off...
I have several different brands of all of them, (in different form-factors) except JIS. I've only got a couple of them, since they are pretty rare around here. I only ever see them in Japanese-made equipment/tools.
The only hinge-manufacturer branded one I have though is Grass. We have a sales rep that carries a box of them in his car and gives them away. That Blum is a lot nicer, more modern looking.