As others said, libreoffice
can convert xls files to csv. The problem for me was the sheet selection.
This libreoffice Python script does a fine job at converting a single sheet to CSV.
Usage is:
./libreconverter.py File.xls:"Sheet Name" output.csv
The only downside (on my end) is that --headless
doesn't seem to work. I have a LO window that shows up for a second and then quits.
That's OK with me, it's the only tool that does the job rapidly.