Default Xarray combine parameters

Xarray's default combine operations are overly permissive and can lead to unintuitive behavior and poor performance. Guidance for better arguments can be found in the xarray documentation and issue proposing stricter defaults.

With Xarray v2025.08.0 or later, you can opt into more consistent behavior that does not load data by default using xarray.set_options(use_new_combine_kwarg_defaults=True).