Into a large mixing bowl crumble the vegan ground beef and sausage. Add the flax egg mixture, pretzel crumbs, vegan cheese, red onion, Worcestershire sauce, garlic, cayenne pepper sauce, sea salt, and ground black pepper.
Using your very clean hands, mix everything together until evenly combined.
Divide mixture into 6 equal portions for burgers or 12 equal portions for sliders. Form into patties by rolling each portion into a ball. Then, using the palm of your hand, flatten to desired thickness.
Place patties on the preheated grill. Cook for about 7 minutes per side, or until heated through. An instant-read thermometer inserted into the center should read at least 160 degrees F.