@t36s hey, to answer your original question: files should get black-listed if they a) are not a VST plugin, b) have the wrong architecture or c) crash during probing.
Unfortunately, certain plugins don’t seem to like each other, meaning that if a certain plugin is loaded, another plugin might refuse to load. I won’t got too much into details, but I think I’ve more or less fixed this in the current development version. Can you please replace your VSTPlugin version with that one: https://git.iem.at/pd/vstplugin/-/jobs/7206/artifacts/download
First do VSTPlugin.clear; to clear the plugin dictionary and remove the cache file, then perform a new search with verbose: true and post the console output.