Cool question!
I’ve seen Niagara ingest data from static/skeletal meshes, but I’m not sure about lidar data.
This thread mentions importing the lidar data to houdini and then importing from houdini to niagara.
In the 5.0 Content Examples project → Niagara_Advanced_Particles map → example 1.4 shows niagara sampling the g-buffer. (Could be used in conjunction with lidar data maybe?)