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
It's cool that you're trying to make auto generated thumbnail better, but let's be honest, anyone who uses default thumbnail don't put too much effort into their videos.