I updated to LO 6.1.5 (and then 6.2) but found in each case that creating a new sheet by copying an existing one is very slow (5 to 10 seconds), versus the fraction of a second that was previously required. Is there some setting change that I should make?
My app creates new sheets by copying a model sheet, loads data into each sheet, and summarizes that data in still another sheet in which the app has generated unique formulas for each sheet. I was disabling Automatic Calculation before these steps and (supposedly) re-enabling Automatic Calculation after all had completed. For some reason, between versions 6.1.4… and 6.1.5, the behavior changed and Calc apparently did many more recalculations, consuming several seconds. I moved the formula-generation and re-enable steps farther down in the list of things to do and got the speed back up to where it was before the upgrade.
I am satisfied that there is no performance problem in the Sheets.copyByName method, and that judicious use of disabling and re-enabling Automatic Calculation can have a major effect on performance.