Another egg substitute vegan D uses is the liquid from a can of chickpeas—called aquafaba in the vegan cooking world, apparently. Chickpeas are rich in protein so the liquid can replace eggs in some recipes.
One may have to google “vegan recipes using aquafaba” to find applications. I think D has made cakes with ‘chickpea juice’, as I jokingly call it.
The negative to using it is that once the baking is done, now you gotta find something to do with the chickpeas in the fridge!!