Automatic vs. manual
Manually choosing an appropriate projection for your spatial data can be tedious.
In most cases, automatically choosing a projection for your data can accomplish your analysis without visible side effects. By default, mundi.py will choose the projection expected to minimize distortion for your operation, and will convert geometries back to latitude and longitude (EPSG:4326) after the operations.
GeoPandas also has
gdf.estimate_utm_crs(), which is similar but not the default.
If desired, projections can be chosen manually. This article may be a helpful guide if you need help choosing.