there is a better open source meta search engines

I already use Searxng and have never used Kagi, but I’m curious why you say that Searxng is “better.” Are you saying that because the quality of the searches is better, because it’s open source and Kagi isn’t, or for some other reason?

What alternative do you use for indexed searches of the fediverse? Do any of the open meta engines allow source ranking like Kagi does? Looked at the git changes. Think you will need to point out the shady ones. It's not inherently obvious. Do you have a specific recommendation for an open Kagi competitor (that has fediverse indexing as mentioned)? I've heard people talk about DDG options and those pale in comparison with real world use in my use cases.

Edit: also, your title reads like you are making an effort toward being insulting or derogatory. It's not a great way to initiate productive conversation.

I have been contemplating moving to SearNXG for a few weeks, but I have a hard time finding whether I can configure things like domain down-ranking/blocking or custom bangs and lenses, does anyone know if you can do that on a user or instance-level?

The page you linked clearly explains that they use other search engine sources, which makes your post either wrong or intentionally misleading:

Our search results also include anonymized API calls to all major search result providers worldwide, specialized search engines like Marginalia, and sources of vertical information such as Wolfram Alpha, Apple, Wikipedia, Open Meteo, Yelp, TripAdvisor, and other APIs. Typically, every search query on Kagi will call a dozen or so different sources simultaneously

I like and support Kagi. Whatever.