Here are the new (left) and old (right)pads..
It is easy to see that the chamfering has been done by eye and not with any accuracy. Look at the far right, the chamfer edge is almost curved!!
Interestingly looking at the old pads they are more worn where the upper, larger, piston applies force and slightly less worn where the lower smaller pistions apply force.
The three pistons are all different sizes with latgest at the top, mid size in the middle and smallest at the bottom...:why?
On 6 pot bike caipers I've had the upper and lower piston are the same size, the centre one smaller. !