Sharing answers to top q's we’re seeing about the thumbnail experiment: – Custom thumbs aren't going away – 99.7% still see the creator's custom thumbnail – A lot of creators use auto-generated thumbnails, this test helps improve them for those using them: https://goo.gl/A7oDmr
Little late here, but as a hobbyist creator, thumbnail making is one of the easiest things. GIMP and 10 minutes (usually done while the video is rendering) and that custom thumb is vastly better than anything generated. Only time I use auto is when I dont care about the thumbnail