This is excellent work and I adore the result, but I can’t help but feel like the effect could have been achieved with crafted texturing. If you look at Sketchfab as often as I do, there are artists achieving this kind of thing purely with textured polygons[0]. Dynamic lighting is lost with this method, but I feel like with an artist and programmer in close collaboration could find a clever way to solve that.

[0] https://sketchfab.com/3d-models/watercolor-bird-b2c20729dd4a...