I'm working on moving from L&L-23 to L&L-25 and ran across one issue that bit us. We have a few L&L reports that only export to Excel and have quite a few columns. Prior to L&L-25 you could just define the columns, tell L&L not to "adjust" the widths so as to fit in the table and life would be good. I have one export for 55 columns.

With L&L-25 a new rule was introduced which essentially says that all columns must fit inside the table so any that fell outside (off to the right) were simply truncated. Combit said to set option LL_OPTION_SUPPRESS_CELLCLIPPING_TO_REPORTCONTAINER to true to be backward compatible to LL-23 & before rules and that did work for this but unfortunately it also forced the column header names to show on almost every other line, go figure.

Combit got back to me to say that I should set the following:

While printing with "Export only Table Data" (Export.OnlyTableData) to the Excel format you can use the List & Label export option "Header and footer lines = Print once" (see screenshot attached). In your code you can set "XLS.IgnoreHeaderFooterLines" to the value "2" to get the same without user interaction.
And the screen shot didn't really help. The problem is that I can't find anything in cListLabel.pkg that looks anything like that. How can I get the headers to print only once?