Question iOS LiDAR texture mapping techniques?

I'd like to texture the meshes generated by the ARMeshManager. Since ARKit exposes nothing that allows me to do that out of the box, what are the techniques used into achieving something of the sort?

Also, I've noticed an app that allowed a higher resolution for the meshes and depth limitation. Since again, ARKit exposes nothing of the sort, I'm assuming they build their own mesh instead of using what's provided by Apple. What are they building their mesh off of?