His feet look quite tough to me. Good big knuckles. It's my opinion that the strength and toughness of ligaments and tendons means far more than the shape of the feet, hence the flatfooted bull crosses and saluki crosses that stay sound.
Now for the controversial bit! Ligaments and tendons increase in size while a pup is growing and once the pup is fully grown they (ligaments and tendons) don't grow anymore. Muscles grow in response to work but ligaments, tendons and cartilage don't do, not noticeably anyway. Because of this it's my opinion that a pup intended for work should be allowed