The TPG diet is fine as long as you are using the supplement that is supposed to be fed with it. It's well known diet also known as the Priscilla Price diet, and the Pet Glider Fresh diet.
Let me expand on the blended diet. By "blending" I mean, putting fruits and veg in a blender until they become a smooth, slurry, liquid, no longer chunks of fruit. Slushies, slurries, puree, baby food are blended. This is what CocoaPuff was speaking about.
TPG is a "blended diet" in the sense that everything is thrown in a bowl and blended ( STIRRED ) together and served as one complete thing rather than fruits and veg on the side like Bml uses, but the fruits and veg are still intact in the tpg diet, maybe chopped up, but not in a liquid form. This is just fine the glider is able to eat the digestible parts of the fruit and veg and leave the rest if there are any, like skins from the kernel of corn, pea shell, the shell of a green bean.
CocoaPuff you did a good job explaining why fruits and veg in a blender is not a good idea