Making the source code for a seperate free tier search engine (if one doesn't exist already) open source. It would almost be like two different search engines (the free "community edition" one influenced by the community, and the paid one made by the Kagi team).
The free tier could act as a sort of "sandbox" where new features suggested by the community could be implemented and tested at a much faster rate than what would be possible with a small team looking at the forums. Whichever features that significantly improve the Kagi user experience could then be implemented on the paid tiers as well.
Instead of solely relying on this forum for suggestions and improvements (as well as how to implement them), users that have suggestions for improving Kagi and the programming knowledge to do it themselves (at least to a rudimentary degree) could fork the "community edition" of Kagi and implement their idea there. Other users could also improve on that idea, building upon it and making it better. A PR could then be made on the Kagi Github which (if satisfactory) could then be implemented for the free tier.
This model is called Open Core, and is already being implemented by companies such as GitLab and Red Hat.
It is basically like the Kagi Feedback Forum, except allowing users to express how their potential feature would work in much more detail than trying to explain it in words.
