If, when and how your site is included in the search results of web search engines depends on a series of factors. Some of these factors are controlled by the search engines but some can be controlled by you as a user.
In general, we cannot determine how long it takes for different search engines to find and index your Scroll Viewport site and all its content.
How long it takes to be crawled and indexed by a search engine can be impacted by:
the specific search engine (and their crawling and indexing approach)
the content and theme choices you make for your Viewport site
the proactive steps you decide to take in order to be indexed by a search engine
Using the Google Search console to appear in Google Search results
You can take a series of proactive steps to control a search engines' ability to find and parse your content.
Once indexed, SEO-wise Scroll Help Sites perform better than public Confluence pages. As static HTML sites, Scroll Help sites are more focused on content than public Confluence pages, which load a lot of content-unrelated page elements.