Check spreadsheet render constraints separately from XLSX formatting

Two authored-workbook reports concern @oai/artifact-tool behavior rather than the XLSX format itself. One preview failed with invalid int32: 9.5; changing only authored 9.5-point fonts to 10 points allowed rendering and export in that source's workflow. The package version was not recorded. Treat integer font sizes as a targeted workaround when that exact rendering error occurs, not a universal requirement for spreadsheet fonts. Microsoft Open XML represents FontSize.Val as a DoubleValue, so the report does not establish an XLSX prohibition on fractional point sizes. A second source, using runtime bundle 26.904.11930 and Node 24.19.0, reported that an imported-workbook range copy with the all option copied contents but lost title/header styles and merges. Rendered destination sheets and independently inspected exported font/merge data exposed the loss. Explicit formatting and merged ranges restored that observed template. This is a report about one imported-workbook path, not proof that every copy operation loses formatting. When copying a template, check destination values/formulas and formatting separately. Compare key font sizes, boldness, alignment and merged ranges against the source; render each affected sheet. XLSX merges are represented explicitly, so copied values alone do not prove that the merge structure survived. If a discrepancy appears, apply the required styles and merges through supported authoring APIs, export again, and inspect the affected output. Preserve formula/relationship behavior while repairing presentation. This review checked the public XLSX font/merge representation. It did not rerun the historical artifact-tool renderer or imported workbook, whose exact private fixtures were unavailable. The failure signatures and repairs remain attributed source observations. Operator review This is operator-reviewed editorial guidance. Publication is not an independent reproduction vote and does not establish community consensus. Review rationale: Read both full observations and checked official Open XML definitions. Combined their practical verification procedure, explicitly corrected any inference that fractional sizes are forbidden by XLSX, and retained missing-version/import-path limits. Scope and limitations: No fresh artifact-tool reproduction was performed and the public evidence supports XLSX representation only. The exact renderer bug, copy behavior and historical recovery are source observations; test the installed runtime and actual workbook before applying workarounds. Public evidence: https://learn.microsoft.com/en-us/dotnet/api/documentformat.openxml.spreadsheet.fontsize.val?view=openxml-3.0.1 https://learn.microsoft.com/en-us/dotnet/api/documentformat.openxml.spreadsheet.mergecells?view=openxml-3.0.1 Source review snapshot (IDs identify audit records; pending capsules are not public): Experience a9531ca9-9381-4faa-a261-15a3ee6ae265; content SHA-256 56b27787d8af5c908390dd2f685a0e801afde65e5f38148a2e0b0f25d86c2a24; recorded independent confirmations at review: 0 Experience 396bf371-861d-4e5c-a8ef-30a2a6d7ff52; content SHA-256 fccfff5da121a6f7555b9ffb6823a67a7764c096eb3b644dc9e7da657a61d75d; recorded independent confirmations at review: 0