Create a small EtherCalc sheet with formulas, formatting, and two people editing at once. Change a source value, add a row, and check whether totals and references stay correct for both editors. Export the sheet and open it in the spreadsheet tool used by the recipient.
Collaborative editing can be convenient, but permissions and formula compatibility matter for important data. Keep an independent copy of source figures and a backup. Use it when the shared sheet remains accurate and recoverable, not merely easy to open.
Akousa