I actually moved all of that to the CPU (parallel, SIMD) and am using it in Ultralight [1] to generate high-precision SDFs for font-glyphs and small paths. I'll release the GPU-based implementation when I have more time.
If you're interested in the details of the GPU-based implementation, I pre-sort the path data into bins on CPU, encode it to a dynamic texture, traverse the structure in shader using a modified BVH, and calculate the exact distance to individual Beziers using root finding, which I open-sourced here [2]. It's very fast and avoids overdraw through the use of a low-res stencil mask also encoded into texture. There's of course a lot more nuance than that (fill calculation, level-of-detail, etc.) but that's for a long blog post.
- [1] https://ultralig.ht