Seems that the BlockTripwire class doesn't trigger BlockPhysicsEvent at all, I think it's triggered elsewhere, probably in the World class in the notifyAndUpdatePhysics function.

The problem is that this limitation makes impossible to cancel powered attribute change when a player stands on the Tripwire or a Tripwire Hook is attached.

You can notice that in the `private void a(World world, BlockPosition blockposition)` method of `BlockTripwire.java` file.

No BlockPhysicsEvent triggered, so the blockstate is changed to powered: true/false without any check even if the event is catched and cancelled.