YES, YES, YES!! Finally, a working replacement for the various extensions of this type that have come and gone, especially "Ratings Preview for YouTube" which was sold in June 2018 to a questionable owner (and which stopped working for me recently anyway). I am so happy that someone has stepped up to write a new one and I hope you continue to maintain this and keep it working. A Chrome version is available too (https://chrome.google.com/webstore/detail/youtube-thumbnail-rating/cmlddjbnoehmihdmfhaacemlpgfbpoeb)

Thank you Elliot! As they say, "You the real MVP".

Works as intended, thank you

LOVE IT, a must have I think, a really cleaver addon :D

Excellent developer! Very responsive to comments/feedback and pushes updates quickly! Great alternative to Ratings Preview which doesn't work for me anymore :)