To integrate this into coracle or flotilla or any client, see
https://brainstorm.world/developers. You'll be querying a relay with the search string and observer pubkey using NIP-50, not an api endpoint.
New users will by default be shown the "global" point of view (called the "House PoV"), which in this case means the PoV of NosFabrica. From a practical perspective, the global view will work perfectly well the vast majority of the time for the vast majority of users.
It's open source so you can run your own instance and define House (global) as hodlbod or flotilla or coracle or whatever pubkey you want.
To personalize scores, right now it's a one-time setup of 20-30 minutes but we're working on getting that down by at least an order of magnitude. And once it's set up, its' faster and more performant than whatever alternative you may be thinking about.