I have a question

I'm building a tool to discover hidden PBNs (sorry guys, we all have to eat) and I have a question related to PBNs, if someone wants to give me an insight, as I don't have too much experience with them.

I've found two domains, on a ccTLD and the content is in English, related to gambling niche, both domains with 2-3 posts (one per day). The problem is that all articles don't have backlinks, in the articles, but only one backlink at the top, that tells the user "How to use ...(betting platform)".

The question is, will those PBNs will include in the future backlinks in the articles or will remain as is, with a link at the top?

I think if you are making the tool, then the tool will have to crawl the web regularly to see changes in the indexed content for hyperlinks. This cannot be a one-time crawl affair. I can show you PBNs in my kitty where there exist 14 articles of varying length but just one link to a money site, so that's not a criterion.