To account for DEM uncertainty during coregistration, we need our own "weight-supporting" ICP functionality.

It seems fairly straightforward to code, here are some implementations we could base ourselves on and give credit to:
Basic implementation: https://github.com/ClayFlannigan/icp
Implementation of CODEM (looks like it supports weight): https://github.com/NCALM-UH/CODEM/blob/main/src/codem/registration/icp.py
SimpleICP existing in multiple languages: https://github.com/pglira/simpleICP/blob/master/python/simpleicp/simpleicp.py