Something that would really help push optimization that extra bit would be to consider building in a feature to optimize image textures. I often find that the optimizing geometry can only go so far when your model still has the bloat of high-res textures. I’m envisioning something like JPEGMini built-in as a slider in the material rollout. At this point, I run textures through SketchUp, but building this feature in would help skip a step (or many steps with multiple materials)
Just for your consideration - keep up the good work! - Corey