Half a year ago i was browsing this forum and i found a topic with the "selection keymaps". A man posted a screenshot with keymaps settings but it was some advanced selection settings. It wasn't some "mesh.loop_select" stuff, it was some deeper select keys. Under that setting he opened a minimised window with more settings like on my screenshot with "Box Select".
I can't remember what it was. I was looking a whole day trying to find this page. Im sorry, but maybe someone will understand what i mean and help me.