Hello, I have this problem:
I have a rig where I use spline IK setup. It is cyclic(as it has to be with the current rigging system limits : ( ), so it’s like this: controller bones ->empty>hook inside curve>control mesh deformed with curve modifier>vertparended emptys> bones constrained to these emptys. That’s a reason that the rig lags.
I’ve fixed this for render with a sciptlink, in the script i use scene.update()to have 1 more recalc, so it works nicely. But the update of the whole scene is slow, so I wanted to call a function just to recalc the armature pose. If you can help me with this, then please respond. But don’t just post links to the Api doc, I’ve been there. thanks.
I uploaded the rig itself for more clarification - use it if you want, but I have to warn you - it still lags 
But otherwise it’s free for any purpose and modification. If you manage to get it better, please let me know.