Where the old output broke
Merged cells often caused headers to split apart or drift into the wrong column when a workbook was converted to Markdown. That made otherwise useful tables feel unreliable, especially in finance sheets, inventory exports, and quarterly reports where one broken header can change how the whole table is read.
What changed in practice
The converter now does a better job preserving header grouping and row order in dense spreadsheets. It is not magic ? very ornamental spreadsheets still need review ? but routine business tables now come through with less cleanup and fewer surprises.