The Worksheets indeed does not have the auto row height functionality. The solution to that is to select a big range of rows on the client-side and set the wrap property to true, which will adjust the cell height, hence affect the whole row height.
Another option is on the server-side to iterate over the generated cells and set the .Wrap property.
There is also a feature request for the underlying Kendo UI Spreadsheet widget where you can follow the feature progress and cast your vote:
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