Not vegan but I appreciate the effort you’re putting in, so I’d like to chime in.
Lentils. I always had issues with lentils in soup. Even with canned lentils that ideally don’t need soaking. Half would break apart and the rest would still be whole. A while back I bought a pressure cooker (sunbeam multi function) and it’s been a great for lentil based soups/stews. All the onion, herbs lentils, pearl barley, wheat (?) and so forth go in then I pressure cook it. Then add root veggies (carrot,potato,etc) I don’t want turning to mush in after and simmer them for ten minutes. Been a god send for breaking down the lentils and stuff I want while keeping the other veggies firm for texture. Literally swap out one ingredient for tofu and it’s vegan. Previous partner was vegan so I like having some recipes that are easy to make vegan for mates.