In theory the point density node is a powerful tool to get particle and mesh data such as vertex weights inside your node setup.
I’m praxis however it’s quite buggy, incompatible with eevee, error prone and I honestly can’t remember it ever working properly for me.
These are all from the last few weeks:
https://developer.blender.org/T71296
https://developer.blender.org/T71309
https://developer.blender.org/T67718
Since there is probably no time to actually fix it, wouldn’t it be consequential to remove it for the time being, or hide it behind the experimental settings like adaptive subdivision?