...the wear witnessed so far appears abnormal and not what I'd expect for a quality blade...
I'm new to this forum, but not to farm equipment. Here are a couple of thoughts:
I own a Land Pride GS1572 Grading Scraper, and so far I'm very pleased with the way the blades are holding up. I've put roughly 30 to 35 hours on the scraper in a variety of very rocky soil and road conditions here in Maine, and the blades still look very good, with much less wear and tear than I expected. I've also used the scarifiers a fair amount, and they still look good.
Other factors besides metal composition can affect the longevity of the blades, such as the mass, shape, hardness, toughness, and texture of the rocks that they strike, how firmly embedded the rocks happen to be, how numerous the rocks are, the mass of the scraper, how fast the scraper is moving when the blades strike rocks, etc.
I'm quite conservative when it comes to operating speed. I always try to use my equipment at speeds that I consider safe, efficient, and easy on the equipment. It appears to me that when ground engaging equipment is operated at higher-than-optimum speeds, the cutting edges seem to accumulate more damage or wear relative to the amount of work done, due perhaps to increased linear momentum and greater collision energy with rocks or other obstacles.
I don't know the speeds at which you operate your scraper, and I could not venture a guess as to what your optimum grading speeds would be for highest safety, efficiency, or blade longevity, since I am not familiar with your specific operating conditions and equipment. However, you may want to research the topic carefully. Perhaps the manufacturer has some technical support people who could give you some suggestions regarding operating speeds or other factors.