We actually had that in the course just last week. :)
A meat-free diet is theoretically not unhealthy for an adult dog. I would never feed a growing dog (i.e. yours, until he is fully grown) a meat-free diet, as their needs are much too specific. Sick or old animals should not be fed a vegetarian diet either.
Just like us humans, dogs have naturally defined nutrient requirements. They need proteins, fats, carbohydrates and additives (vitamins, minerals). There are guidelines for those (FEDIAF). The only important thing when choosing a food for your dog is that the daily rations contain all the essential nutrients.
One of the most important components of a dog's diet is protein. This is usually obtained from meat, but obviously not in vegetarian or vegan food. And not all dogs can tolerate eggs or dairy products. So, plant-based alternatives such as lentils, peas and carrots are used. However, in most cases this is not sufficient. The proportion of proteins and amino acids is always too low in most vegetarian foods. And the vitamin B12, which is essential for dogs, is almost completely absent. There are also often deficiencies in taurine, phosphorus, calcium and sodium. The problem is that although many owners today tell you that they are completely happy with their meat-free dog food, is this really the case? In fact, it is all too often assumed that a dog that appears agile is automatically healthy. The fatal thing about this is that deficiency symptoms often only show up years later. So if you feed your dog a vegetarian diet but don't have regular blood tests, you won't know about the deficiency. The vet showed us an x-ray of a dog's skull with deficiencies - it was completely brittle and full of holes. And then she showed us a video of the same dog in the park - you would never have thought that this dog could have any deficiencies. But he came to her with a kidney failure.
You would have to look at your chosen food in detail and calculate whether it meets your needs based on guidelines. Don't do it by yourself and don't trust the manufacturers, consult a good nutritionists (definitely not one of those with a holistic or "spiritual" approach, you need numbers and hard scientific facts. Most vets also don't specialise in nutrition). One thing in advance: a food that is advertised as ‘without additives’ can never meet your dog's needs (even non-vegetarian food needs additives).
Insect foods are another matter altogether; you would have to calculate each one as well. But, you have to rely more on the manufacturer's information regarding the protein content, etc. than with a ‘normal’ food, and this information is usually not checked by an independent body.
Omni does not provide any information about the calcium:phosphorus ratio in the food, maybe you could get the information on request, but that would put me off the food on principle.