Integrated my curves editor into the existing in-game UI. Now the hard part is not using curves for everything under the sun. I'm not sure if I want to make a dopesheet et al too as I'm not remaking blender. Basically for the in-game editing you can click a 'button' to pop open the curve editor for a given curve. This is also controllable from Lua script and remote HTML / telnet sessions into the game of course. I'll refine the prototype a bit more with wrapping modes, better UX, et al.