When merging files that contain the "159 '\u009f'" char, ArgumentException("The encoding is not supported.") is thrown.
Implement support for cell references to columns and rows, e.g. $1:$2, A:D, etc. Currently, CellSelection.SetValue throws ParseException, and CellSelection.SetValueAsFormula throws InvalidOperationException.
Currently, PdfStreamWriter writes only PDF pages. If we implement API for merging multiple pages or whole documents we would be able to preserve links between pages (which are currently being corrupted). Merging whole documents would also allow preserving document properties (bookmarks, interactive forms, ...). For a more detailed list of the unsupported document properties you can refer to our documentation: https://docs.telerik.com/devtools/document-processing/libraries/radpdfprocessing/formats-and-conversion/pdf/pdfstreamwriter/features. We may also implement API for adding initial document properties from some existing PDF file.
Implement import of PDF to RadFlowDocument, using PdfFormatProvider. This would require text recognition (including determining where paragraphs end as opposed to new line inserted because of the layout) and table recognition. This will allow conversion of PDF documents to docx, RTF and HTML.