A way to evaluate the child callback function on Motion?

I have a component that renders to WebGL using virtual child components outside of the DOM reconciliation (basically a custom WebGL renderer). Is there a way that this parent component can host utilize `Motion` elements as children, and invoke the callback child function to obtain the results?

Review Motion's child-function behavior and the custom WebGL renderer context described in the issue. Determine whether Motion can expose evaluated child results to a non-DOM parent; done would be a documented supported integration or a clearly scoped API change.

Written by the indexing model from the issue text.