I have not been able to find any instances of an itch.io staff member directly stating that search results are truncated (the only person I found who suggests this is you, oddly enough). What I did find was multiple instances of the staff clarifying that search results are optimized for searching for exact titles.
"The box is optimized for exact title searches, that's what. Searching by keywords is a matter of luck." (No Time To Play, Why is the search function of the store so limited?)
I've said this in other posts, but essentially search is suited for finding things by direct title, not by topic. Tags are how people browse things by topic. People do not browse by topic...through our search engine. Hope that helps. (leafo, My game doesn't show up in search or tags)
"Our search engine is optimized for Direct title search since that is how the majority of people use search. For users who are browsing for new games, we try to push them into our browse pages with tags, which are surfaced on the top of the search results. This means that the text in the body of your project page and any tags you add will not become search queries for your project. Tags are only for our browsing pages, which are separate from search." (Limitations of Search, Getting indexed on Search & Browse)