I have not tried this but yes, your theory about particle system should be correct- use your deforming mesh as a mesh particle, then use lifetime (which is 0-1) multiplied by your number of frames, and input to the ‘frame’ input in openVAT_standard. This could be a good case I can add to demos
The vertex animation output using this add-on worked perfectly in Unity! I hope that this add-on will grow into a standard VAT tool between Blender and Unity.
By the way, how can I make this FBX appear as a Particle in a ParticleSystem and animate it? In ShaderGraph, it seems like I could just input the Particle's Lifetime to one of the ports of the openVAT_standard node.