According to Product Management for Reports:
"Customer cannot do an insert after an import into the same workbook. Customer will need insert each report into a new workbook. This is discussed in the "Working with Reports in Smart View" section of the Reports User Guide. "
However, in Financial Reporting, this is allowed. Noting that we are losing key features that were available in Financial Reporting and that are not available in Reports, which mandatory to migrate to in order to continue receiving support.