I don't think any ratio variant could mess this up. The second sauce hack involved a lot of sour cream I've never made a pasta sauce with sour cream, and I was both worried and intrigued by ...
Put the silken tofu and soy sauce in a tall jug and add 3 tablespoons of the reserved pasta water. Use a stick blender to blend to a smooth sauce, then pour into the pan with the mushroom mixture.