If you are using that much oil, it is most likely from torched ring lands and literally blowing oil into the combustion chamber. The first time you pulled the plugs and they looked like that, I would be pulling the engine. When the tips of the plugs come off like that, most of the time it bounces around and will damage the valves, pistons, and sometimes the cylinder walls from the debris. Especially the porcelain pieces. That stuff does NOT burn so it gets thrown around.
The more you drive it, the worse the damage will be. Stick a boroscope down the spark plug holes if you doubt this.
I'm guessing that this was the second forged engine?