Address dashboard performance when using large files

The streamlit dashboard has a 200mb file size limit. Approaching these sizes slows the dashboard down significantly and sometimes results in a complete failure to display a plot:

This should be addressed with smarter storage of data, including only the necessary number of significant figures.

Start by locating the Streamlit dashboard's data-loading and storage path, then reproduce the slowdown with a file near the 200MB limit. Done means large files no longer cause the dashboard or plots to fail, while stored data retains only the necessary significant figures.

Written by the indexing model from the issue text.