A lot of people are saying that using a industrial grinder is better for flint but the speed that it turns stone into flint isn’t worth the waist of resources. Depending on your server settings it’s probably easier and much faster to just hit rocks with a metal pick instead.
Anky with a whip is the best by far. Make the anky over encumbered then whip to to the next rock jump on and harvest, then get off and whip to the next rock and so on. (You can whip a dino that is over encumbered and it will always move no matter the weight)