Hi @gabriella and @andylead, thanks for your comments.
At the moment per page control of indexing options is not yet available, but it is possible to prevent search engines from indexing certain pages on the site using a custom domain, using the Robots.txt commands on the SEO tab of site settings.
See more about those commands here: The Web Robots Pages
One suggestion I would have, is to keep the webflow.io subdomain set to have the indexing of the webflow.io subdomain turned off in the SEO tab of site settings: https://help.webflow.com/article/how-to-prevent-search-engines-from-indexing-your-webflow-site
When updates are made, publish changes to the staging version of the site on the webflow.io domain and when ready.
See more about publishing to different target domains here: https://webflow.com/blog/publish-targets-and-domain-redirect
I hope this helps!