So, is that the case that the render procedural is fundamentally a compiled graph saved as bgeo that gets invoked? If that's the case, can we make our own by just changing the bgeo, and the python that configures the procedural? I have my own hair deform for example, the stock one always seem to not work well enough.

there is some earlier discussion about this here [www.sidefx.com] as well as some licensing implications

We still consider these to be shark-infested waters, but we're happy to throw in a life preserver as needed