I have no test case to show but maybe my question can be answered without one.
My DataTables table can be set to have the leftmost three columns as FixedColumns. On top of the complexity that this creates, the first column contains an ID number but appears as a checkbox (it gets rendered into a checkbox by aoColumnDefs and mRender).
Without the FixedColumns in place, the checkboxes can be used (I gather their values into a textarea before sending the form that contains the DataTable), but when FixedColumns is in place, the checkboxes appear as undefined for the javascript that copies their values - I assume because FixedColumns creates a separate table.
How would I address the checkboxes that are part of this separate table?