Why not saving your data in a glTF file? A single glb should produce much better results as a raw text file. Besides, it also possible to compress your data with Draco in order to reduce the file size even more.
BTW: We already discussed a similar topic right here: Can I show a sequence of pointclouds in browser?
Why is using morph targets not an option for you? As far as I understand, you are going to visualize a sequence of independent THREE.Points objects, right? I’ve already mentioned in the other topic that this approach is not really performant…