Mixing IK/FK actions with bvh

I’m working on a somewhat complex animation. It’s a human model falling from the sky, standing up and walking. For the walking I am using bvh, which only works with fk. The falling down, and standing up is going to be so much easier to do with ik. The rig has an fk/ik switch and I can keyframe influence. If I make the two actions and turn them into strips I can keyframe the ik influence on the main timeline and it works (mostly) But that value is hard coded into the timeline. If I modify the speed of the clip, it’s not going to match. Any ideas/thoughts on mixing ik and fk strips? Thanks in advance.

I think I figured it out, but if anyone has any other ideas, please share.

In the actions themselves. I keyframed the ik influence on the first and last frames of the actions. 1 for the fall, stand up. And 0 for the bvh action.

I needed to hide all the fk controls for the fall/stand up as the keyframes were messing it up, even though in theory their influence should be 0.