Nice work. From another comment I see that you chose this project in part to learn three.js, but you might also consider using deck.gl or kepler.gl.

They provide higher level visualization primitives and are optimized for performance with large datasets. They would also allow you to try out different visualization methods more easily, or even overlay multiple ones.

Both packages allow for very fast prototyping (with kepler.gl, you might be able to mock up something with no code at all), so trying out this approach shouldn't involve an enormous amount of work.

Good luck!