Yes, I realise this situation is about as far as one can get from an ideal game optimised solution.
I am creating for a non-game walkthrough experience where the platform for playing the package is a controlled environment (always the same rig). A low frame rate is also not such an issue either.
I regularly import massive scenes to unreal with hundreds of furniture pieces and thousands of props. All with their own materials and get laughable frame rates around 10-30fps which is still workable for what I need.
I would be very interested if there is a way to drive the lerp with a timeline, whilst that lerp is itself used for all these meshes and starting at a variable time (based on distance to growpoint).