Hello,
For those that are interested, I have been able to tweak the Blender exporter to grab the vertex positions of a mesh over time and save it to metadata.
As this comes straight from Blender it will also support PC2, MDD and animated modifiers. Files could end up quite large though if there's a lost of frames and / or a dense mesh.
Clearly there's an issue with missing faces but here's a PG: https://playground.babylonjs.com/#XIF0AK#1