Creating a rule that downloads (potentially large number of) files over a remote and moves the files to a directory on the local file system for further processing/analysis is useful for more centralized data management. However, even when the files have been downloaded locally, checking for a newer version (or however Snakemake decides whether a file has changed) over a remote can take a significant amount of time. This slows down running any other rules that depend on the inputs.
To speed things up, a switch like
--ignore-updates could be used to tell Snakemake to skip checking for newer versions of (remote) input files if all the files are already present locally.