This is correct, there are no online databases that are up to date yet explaining where these materials are specifically found. Some will mention what state or faction alignment it must be, but does not tell you what other status flags overwrite the chances by other materials. For example, if you need Core Dynamics Composites, you have to go to a federal system and search High grade signals. No site will mention that it has to be "High Grade" nor does any site mention that other flags such as Boom will completely remove all Core Dynamics Composites from HGEs and turn them into Proto Heat Radiators. Maybe because it gets complicated at this point. In the system, you have to check and make sure no factions are in a boom state, anarchy state, war, civil war, and possibly others. The more that are in the "none" state, the more likely you'll find the Core Dynamics Composites.
I can personally validate though that if you go into a system with a lot of boom factions, you'll get those Protos.
I'm assuming there's a weird way they programmed in the chances that various components can be found perhaps by an untintentional hierarchy. If anyone were to make a site that listed these off with the best detail, they'd probably have to do a large scale study first and some crazy matrix math to figure out the optimal conditions for finding each. Something that considers the state of every faction in the system.