Hi Raj,
I understand the concern about promoting your Power Pages website from Dev to QA using Azure Pipelines, especially with issues like duplicate web pages and broken sites in QA.
To ensure a clean and reliable deployment, consider using the enhanced data model and environment variables for all site-specific settings. Add your website and related components to a solution in your Dev environment, then manage environment-specific values using environment variables. This approach allows you to export the solution from Dev and import it into QA without duplicating web pages or breaking the site..enhanced-data-model, environment-variables-for-site-settings
When the site has been deployed, you can continue to deploy more configuration changes using the same pipeline process. You need to clear the cache on the destination website to see the changes.
Please refer to the following documents for further guidance:
https://learn.microsoft.com/en-us/power-pages/configure/power-pages-pipelines
https://learn.microsoft.com/en-us/power-pages/configure/power-platform-cli-tutorial