Feature Request: Add Support for Merged Table Cells in OneNote Interop API XML Schema

I'm writing to request an enhancement to the OneNote Interop API — specifically, the ability to support merged table cells in the XML schema used by the UpdatePageContent method.

With the recent addition of cell merging in OneNote for Microsoft 365, this feature has become essential for creating more flexible and visually organized tables. However, the current Interop API does not reflect this capability, and there is no documented support for attributes like colspan or rowspan in the XML schema.

Why this matters:

• Developers cannot programmatically replicate merged cells created in the OneNote UI. I am the author of the OneMore add-in (github.com/stevencohn/OneMore).
• Automation and content generation tools are limited in their ability to produce rich, structured layouts.
• Imported tables with merged cells are automatically flattened, leading to data loss or formatting issues.

Suggested enhancement:

• Extend the OneNote XML schema to include support for merged cells, possibly via new attributes or nested structures within <TD> elements.
• Update the documentation and SDK to reflect these changes and provide examples.

This feature would greatly improve the fidelity of programmatic content creation and align the API with the capabilities of the OneNote client.

Thank you for considering this request. I’d be happy to provide use cases or collaborate on testing if needed.