The re-scaling has to be done outside of features available in the IKinema nodes and should be implemented in your game logic. This can be achieved a number of ways, one of which is described in item 6.2 of the documentation found here (along with a demo VR project containing the logic): IKinema Runtime Documentation
This example does require the user to assume a specific pose so you can accurately calculate a scaling ratio to go from real-world transforms to game-world transforms. As I mentioned, this currently goes outside the realm of the IK solving features of IKinema, but was a method we implemented which worked well.