Increase Office Script Run Speed

excelhelp2280 

Great to know you sorted that out. Yes, performance shall be better. In addition you may adjust conditional formatting, but that's more cosmetic. Something like

function main(workbook: ExcelScript.Workbook) {
  let selectedSheet = workbook
    .getActiveWorksheet();

  const source = workbook
    .getWorksheet("Sheet1")
    .getRange("A1:BC1")
    .getUsedRange()
    .getValues()[0]
  
  const maxRowsInSource = 10000

  const targetNames = selectedSheet
    .getRange("A1:BC1")

  const numberOfNames = targetNames
    .getCellCount()

  const headers = targetNames
    .getValues()[0]

  for (let i = 0; i < numberOfNames; ++i) {
    targetNames
      .getCell(0, i)
      .copyFrom(
          workbook
            .getWorksheet("Sheet1")
            .getRangeByIndexes(
              0,
              source.indexOf( headers[i] ),
              maxRowsInSource,
              1
            )
        .getUsedRange()
      )
  }

    const duplicateRule: ExcelScript.ConditionalPresetCriteriaRule = {
        criterion: ExcelScript.ConditionalFormatPresetCriterion.duplicateValues
      }

    const blankRule: ExcelScript.ConditionalPresetCriteriaRule = {
        criterion: ExcelScript.ConditionalFormatPresetCriterion.blanks
      }

    const rangesBlank = selectedSheet
      .getRanges("F2:F3000, I2:I3000")

    const rangesDuplicate = selectedSheet
    .getRanges("F2:F3000")

    rangesBlank.clearAllConditionalFormats()
    rangesDuplicate.clearAllConditionalFormats()

    const conditionalFormatBlanks = rangesBlank.addConditionalFormat(
      ExcelScript.ConditionalFormatType.presetCriteria);
    const conditionalFormatDuplicate = rangesDuplicate.addConditionalFormat(
    ExcelScript.ConditionalFormatType.presetCriteria);

    const presetFormatBlank:
      ExcelScript.PresetCriteriaConditionalFormat = 
        conditionalFormatBlanks.getPreset();
      presetFormatBlank.getFormat().getFill().setColor("lightyellow");

    const presetFormatDuplicate:
      ExcelScript.PresetCriteriaConditionalFormat =
        conditionalFormatDuplicate.getPreset();
      presetFormatDuplicate.getFormat().getFill().setColor("red");
      presetFormatDuplicate.getFormat().getFont().setColor("white");

    presetFormatBlank.setRule(blankRule);
    presetFormatDuplicate.setRule(duplicateRule);

}