That job is to prevent haloing from the edges of the protector. It isn't well known that glass protectors do suffer from a haloing effect and that the black edging prevents that. These are about as good as it gets and for it to still do a good job. They do not impact on any screen area that I use or see.
The edges are very smooth and go right to the edge of the screen and the protector itself is very smooth, way better than the plastic ones in that respect.
I would have preferred a guide template as that would have make application a cinch, but as it stood it was easy to fit, just give yourself time and patience.
Work any air bubble towards a corne and you will find that you can then slightly lift that corner and smooth away all the bubbles. My screen protector is 100% bubble free after a few minutes of smoothing them away.
The result is a well worth it!