UltimateHtmlViewer is useful when generated HTML reports or static app bundles need to be hosted inside SharePoint without breaking relative navigation or forcing users into raw file URLs.

Common fit

• publish generated HTML reports into SharePoint
• keep report navigation inside one modern page
• support deep links via ?uhvPage=...
• apply URL policy controls such as StrictTenant or Allowlist
• use a reusable SPFx web part instead of creating a custom host for every report bundle

Good operating pattern

Use a local profile file under ignore/ for tenant values and client IDs. Keep deployment details out of committed examples unless they are placeholders.