Use case: we use the New-Forms for Excel in a modern Site Collection option to create a new Form. On completion (all questions & options defined) of the form we want to create a copy the Excel document to another Site Collection and start using it there for another target audience. When opening the Excel in ExcelOnline the Insert-Forms-Preview (and other options are grey > see 2nd image), though the Excel contains a worksheet 'Form1' with all the columns as the original one. When opening the original in ExcelOnline all Insert-Forms options are available.
What's the best way to copy a Form for Excel to another Site Collection? (using the Forms UI you can also copy a Form but these are created in the same Site Collection-Library).
1 - Create Forms for Excel in Modern Site Collection Copy of Forms for Excel to other Modern Site Collection > Insert -Forms options are not availableOrginal Forms for Excel > all Insert Forms options are available